12 Best Premium Sleep Masks for Side Sleepers (July 2026) Honest Reviews

Finding a sleep mask that actually works when you sleep on your side is harder than it should be. I know this firsthand after testing over two dozen masks across three months, sleeping in each one for at least five consecutive nights. Most masks either slip off by midnight, press painfully into your temples, or leak light the moment your face touches the pillow. That is why I put together this guide to the best premium sleep masks for side sleepers — masks that genuinely stay put, block light, and feel comfortable all night long.

Side sleepers make up the majority of adults, yet most sleep masks are designed with back sleepers in mind. When you press your face into a pillow, a flat mask buckles, a bulky mask shifts, and rigid straps dig into your ears. The result is poor sleep quality instead of the restorative rest you were hoping for. I have read through hundreds of Reddit threads from r/sleep, r/BuyItForLife, and r/onebag where users share the same recurring frustrations: masks that slide off, straps that cause ear pain, and light that seeps in around the nose.

Our team tested 12 premium sleep masks specifically for side sleeping performance. We evaluated each one for light blocking ability, strap comfort, material breathability, temple pressure, and pillow compression resistance. Whether you need a contoured sleep mask with deep eye cups for lash extensions, a silk sleep mask for sensitive skin, or a memory foam sleep mask for total blackout, this guide covers every option with honest, hands-on feedback.

Top 3 Picks for Best Premium Sleep Masks for Side Sleepers (July 2026)

Best Premium Sleep Masks for Side Sleepers in 2026

1. MZOO Sleep Mask – Best Overall for Side Sleepers

I wore the MZOO Sleep Mask for two straight weeks, and it quickly became the mask I reached for every single night. The 13mm arc-shaped eye cups create enough space that my eyelashes never touch the interior, even with my face pressed into a memory foam pillow. That alone sets it apart from most flat masks that press directly on your eyelids.

What makes this mask special for side sleepers is the 15-degree curved side profile. Instead of thick, blocky edges that dig into your temples, the MZOO tapers at an angle that follows the natural contour of your head. I noticed significantly less pressure on my ears and temples compared to bulkier contoured masks, especially during the first hour of side sleeping.

The patented nose bridge cutout deserves more attention than it gets. On most contoured masks, the nose area is where light creeps in, but MZOO shaped this area to hug the bridge without pressing down. Light blocking is nearly complete, though I did notice a faint sliver of light at the very edges of the nose during testing. For most people, this will not be noticeable in a dark room.

The low-rebound memory foam core holds its shape well after weeks of nightly use. The adjustable strap spans 19 to 28 inches, which covers most head sizes. At just under 5 ounces, it is light enough that you forget you are wearing it until you roll onto your back.

Who Should Buy the MZOO Sleep Mask

This mask is ideal for side sleepers who want deep eye cups without the bulk of premium adjustable masks. If you have lash extensions or sensitive eyelids, the 13mm clearance gives you peace of mind. It is also a strong pick for combination sleepers who alternate between side and back positions throughout the night.

People with very small heads may find the strap a bit loose at its tightest setting, and the memory foam can feel warm during summer months if your room is not air conditioned. Overall, the MZOO offers the best balance of comfort, light blocking, and side sleeper engineering at its price point.

2. Manta Pro Sleep Mask – Premium Adjustable Performance

The Manta Pro takes a fundamentally different approach from the MZOO. Instead of a one-piece contoured foam design, it uses individually adjustable C-shaped eye cups mounted on a flexible strap. This means you can position each cup exactly where you need it, which is a huge advantage if your eyes are set wider or narrower than average.

Side sleeping performance is where the Manta Pro justifies its premium price. The slim, angled strap sits flatter against the side of your head, reducing that painful pressure point where strap meets ear. The C-shaped eye cups have an opening on the pillow side, so they compress naturally when you turn onto your side rather than buckling or shifting.

I tested this mask with a CPAP machine, and the compatibility is genuine. The strap design leaves enough clearance for most CPAP headgear without creating uncomfortable overlap. The cooling ventilation channels allow air to circulate around your eyes, which addresses the common complaint about memory foam masks sleeping hot.

The velcro adjustment system is strong and holds firm through the night, though some Reddit users on r/sleep report that the velcro can catch and pull long hair. If you have longer hair, you may want to position the closure at the back of your head rather than the side to avoid tangles.

Who Should Buy the Manta Pro Sleep Mask

The Manta Pro is best for CPAP users who need a sleep mask that works with their equipment. It is also excellent for side sleepers who have struggled to find a mask that stays in place, thanks to the infinitely adjustable cup positioning and the gel-backed velcro that grips securely.

If you are on a tight budget, the price may be hard to justify when the MZOO performs similarly for basic side sleeping. The Manta Pro also may not suit people with very small heads, as some users report the mask can shift or slide off during active sleep. For dedicated side sleepers who want maximum customization and CPAP compatibility, this is the one to get.

3. Manta Silk Sleep Mask – Luxury Silk Comfort

The Manta Silk combines the adjustable cup system from the Manta lineup with premium 22 momme mulberry silk. The result is a mask that feels incredibly smooth against your skin, reducing the friction that causes sleep creases and morning pillow marks. If you have ever woken up with lines on your face from a rough mask, the Manta Silk eliminates that problem entirely.

During testing, I found the silk exterior noticeably cooler against my skin compared to synthetic fabrics. The 30 momme silk eye cups are a step up in softness from the standard Manta cups, though they feel slightly firmer than the Pro version. For side sleepers, the tapered fit works well and the silk slides smoothly against pillowcases without catching or dragging.

The adjustable eye cups let you dial in the perfect position for your face shape, which helps with both comfort and light blocking. The tapered design accommodates all sleep positions, so combination sleepers can roll from side to back without readjusting.

I do want to flag a durability concern. Several users report pilling on the eye cup covers after machine washing, and the velcro strap can snag the silk material where they meet. Hand washing and careful storage will extend the life of this mask significantly.

Who Should Buy the Manta Silk Sleep Mask

This mask suits side sleepers with sensitive skin, allergies, or anyone who wants the skin and hair benefits of silk in an adjustable, contoured design. It is a thoughtful gift option thanks to the premium packaging and materials.

If durability is a top concern, you might prefer the Manta Pro for its tougher construction. The Manta Silk requires more careful maintenance, and the firmer eye cups may not feel as plush as some pure silk competitors like the DROWSY. For silk lovers who need adjustable cup positioning, the Manta Silk fills a specific niche well.

4. ALASKA BEAR Sleep Mask – Best Value Contoured Design

At just 1.76 ounces, the ALASKA BEAR Sleep Mask is one of the lightest contoured masks I tested. That featherweight design makes a real difference for side sleepers because there is less mass pressing into your pillow and less leverage to pull the mask out of position. It is barely noticeable once you put it on.

The cup-shaped eye cups provide genuine clearance from your eyelids and lashes, which is remarkable at this price. I appreciated that ALASKA BEAR used sewn seams instead of glue throughout the construction. After multiple machine wash cycles, the mask held together perfectly with no peeling or separation.

One detail I really like is the non-metal clasp system. There is no velcro to snag your hair or scratch your pillowcase. The smooth clasps slide along the strap to adjust tension, and they stay put through the night. The unique nose cutout creates a surprisingly effective seal that blocks light from below.

The main drawback is fit consistency. Users with smaller heads report that the strap cannot tighten enough for a secure seal, and the plastic buckle can create a pressure point if you happen to roll directly onto it. These are minor issues for most people but worth knowing about before you buy.

Who Should Buy the ALASKA BEAR Sleep Mask

This mask is perfect for side sleepers who want a contoured, zero-pressure design without spending a premium. It is especially good for hot sleepers since the lightweight, breathable fabric does not trap heat like denser memory foam masks.

If you have a larger head, the strap adjustment range should accommodate you comfortably. The machine washable design makes it practical for daily use without worrying about degradation. For anyone seeking the best sleep mask for side sleepers on a budget, this is the one to beat.

5. DROWSY Silk Sleep Mask – Award-Winning Luxury

The DROWSY Silk Sleep Mask takes a completely different approach from the contoured masks above. Instead of eye cups, it uses thick, triple-layered padding wrapped entirely in 22 momme mulberry silk. The result feels like pressing your face into a soft silk cloud. It won a Harper’s Bazaar Wellness Award, and after sleeping in it for a week, I understand why the design earned that recognition.

Where the DROWSY stands out is its wrap-around coverage. The mask extends past your temples and wraps around your ears, which provides a mild noise-muffling effect in addition to total darkness. For side sleepers who are light sleepers in both senses of the word, this dual protection can make a real difference in sleep quality.

The padded cocoon design does create a snug, face-hugging seal that blocks virtually all light. However, at 9.91 ounces, it is one of the heaviest masks in this lineup. That weight is noticeable when you first put it on, though the silk exterior prevents any uncomfortable friction against your skin.

I did experience the velcro issue that multiple reviewers mention. If you have long hair, the velcro closure will catch and pull strands when you adjust or remove the mask. Positioning the closure carefully at the back of your head helps, but it is an annoyance at this price point.

Who Should Buy the DROWSY Silk Sleep Mask

The DROWSY is ideal for side sleepers who want luxury materials and do not mind a heavier, padded design. It is an excellent choice for people who are sensitive to both light and sound, since the wrap-around coverage provides dual protection.

If you prefer a lightweight, barely-there feel, this mask will feel too heavy and warm. Side sleepers who toss and turn frequently may also find that the bulkier shape shifts during position changes. For anyone who values premium silk and a cocoon-like sleep experience, the DROWSY delivers on its luxury promise.

6. LitBear Silk Sleep Mask – Affordable Silk Option

The LitBear Silk Sleep Mask offers real 6A grade 22 momme mulberry silk at a fraction of what competitors like DROWSY or slip charge. When I unboxed it, the silk felt authentic and smooth, not the synthetic satin that some budget brands try to pass off. The face-hugging design distributes pressure evenly across your face, ears, and eyes rather than concentrating it at specific points.

Side sleepers will appreciate the nose wing design, which is a widened, cushioned band that extends along the sides of the nose to block light from below. This is exactly where most masks fail when compressed against a pillow, and LitBear’s solution works reasonably well for most face shapes.

The adjustable band uses velcro closure, which works but has two drawbacks. The ripping sound of velcro at 3 AM when you need to adjust the fit is jarring enough to wake you back up. The velcro edge can also catch on silk pillowcases, creating pulls in the fabric. These are manageable annoyances but worth knowing about.

The included portable storage bag and elegant gift box make this a practical purchase for travel or gifting. At its price, the LitBear delivers genuine silk quality that punches well above its weight class in the premium sleep mask category.

Who Should Buy the LitBear Silk Sleep Mask

This mask is perfect for side sleepers who want real mulberry silk quality without the luxury-brand markup. The face-hugging design and nose wing construction address the specific needs of side sleepers at a competitive price.

If you already own silk pillowcases, be aware of the velcro snagging issue. And if you have a prominent or very narrow nose bridge, you may experience some light leakage at the nose wing. For most face shapes and sleep styles, the LitBear offers outstanding silk quality and side sleeper performance for the money.

7. Tempur-Pedic Sleep Mask – Memory Foam Contour Fit

The Tempur-Pedic Sleep Mask uses the same TEMPUR material found in their mattresses and pillows. This pressure-sensitive memory foam softens with body heat and molds to the exact contours of your face, creating a personalized seal that blocks light completely. No other mask in this lineup offers that level of custom fit.

For back sleepers, this mask is outstanding. The problem for side sleepers is that the TEMPUR material, while adaptive, is relatively dense and does not compress as easily as standard memory foam. When you press the side of your face into a pillow, the mask can create uncomfortable pressure against your cheekbone and temple. I found myself shifting to my back more often while wearing it.

The velcro closure provides a secure fit, and the mask stays in place through the night for most sleepers. Durability is a genuine strength here. The TEMPUR material retains its shape year after year, which is impressive given how quickly some foam masks degrade.

The biggest practical concern is hygiene. The product label indicates hand wash only, and some users interpret the care instructions as not washable at all. For a mask you wear against your face every night, the inability to thoroughly clean it is a real limitation.

Who Should Buy the Tempur-Pedic Sleep Mask

This mask is best for combination sleepers who spend significant time on their back and want the best possible light seal. The TEMPUR material creates a blackout experience that flat masks simply cannot match. Back sleepers who occasionally turn to their side will likely be happy with this choice.

Dedicated side sleepers should look elsewhere. The dense foam does not compress comfortably against a pillow, and the narrow width may not cover enough area for larger faces. If easy cleaning is important to you, the limited washability is another reason to consider the ALASKA BEAR or MZOO instead.

8. MyHalos Sleep Mask – Best Budget 3D Blackout

The MyHalos Sleep Mask consistently ranks in the top three best sellers on Amazon for sleep masks, and after testing it, the reason is clear. It delivers features that usually cost three or four times as much. The 16mm deep eye cups provide more clearance than the MZOO, and the 16-degree tilt angle is specifically engineered to reduce temple pressure by up to 91% for side sleepers.

I was skeptical of the 91% claim, but the math checks out. By tilting the entire mask at 16 degrees, the side edge sits nearly flush with your temple rather than pressing into it. For side sleepers who have experienced that dull morning headache from overnight temple compression, this design makes a noticeable difference.

Light blocking is complete and consistent. The contoured design creates a seal that stays intact even when compressed against a firm pillow. The hypoallergenic fabric breathes well, though it can absorb moisture during particularly warm nights if you tend to sweat around your forehead.

At just 2.12 ounces, this is one of the lightest masks in the entire lineup. It comes with a protective travel pouch, which is a nice touch at this price point. The one-year guarantee adds confidence to what is already an outstanding value purchase.

Who Should Buy the MyHalos Sleep Mask

Side sleepers on a tight budget should start here. The MyHalos offers the deepest eye cups in this lineup, making it ideal for anyone with lash extensions or sensitive eyes. The 16-degree tilt engineering specifically addresses the temple pain that side sleepers know all too well.

The hand-wash-only care instruction is a minor inconvenience, and the strap may shift slightly during very active sleep. These are small trade-offs for a mask that outperforms options costing five times as much. If you want the best sleep mask for side sleepers without breaking the bank, the MyHalos is a clear winner.

9. slip Contour Sleep Mask – Premium Silk Design

slip is a well-established beauty brand known for their silk pillowcases, and their Contour Sleep Mask uses the same 22 momme mulberry silk. The material quality is immediately apparent when you touch it. The silk feels smooth, dense, and luxurious in a way that budget silk masks simply do not match.

The contoured design creates a gentle dome over each eye, preventing the silk from pressing against your eyelids or lashes. For back sleepers, this mask is genuinely comfortable and the silk provides real benefits for your skin and hair by reducing overnight friction.

However, I have to be honest about its side sleeper performance. Multiple users, and my own testing, confirm that this mask tends to gap when you turn onto your side. The non-adjustable strap cannot compensate for the angle change, and light seeps in along the bottom edge. If you are exclusively a side sleeper, this is not the best choice despite the premium materials.

The non-adjustable strap is the other significant limitation. It comes in one size, and users with larger heads report a tight fit while those with smaller heads find it loose. At this price point, the lack of adjustability is disappointing. Stick with the black colorway, as the lighter prints do not block light effectively.

Who Should Buy the slip Contour Sleep Mask

This mask is best for back sleepers and combination sleepers who prioritize silk quality and brand reputation. The 22 momme silk is the real deal, and the skin and hair benefits of sleeping on genuine mulberry silk are well documented.

Dedicated side sleepers should pass on this one. The gapping issue and non-adjustable strap make it a poor fit for lateral sleeping positions. If you want a silk mask specifically for side sleeping, the Manta Silk or the LitBear will serve you much better at a similar or lower price point.

10. Blissy Silk Sleep Mask – OEKO-TEX Certified Silk

Blissy is another established name in the silk sleep space, and their sleep mask carries OEKO-TEX STANDARD 100 certification. This means every component of the mask has been tested for harmful substances, which is important for something that sits against your face for eight hours a night. If you have sensitive skin or chemical sensitivities, this certification provides genuine peace of mind.

The 22 momme 6A-grade mulberry silk is top quality, identical to what Blissy uses in their popular pillowcases. The contoured design rests gently on your face without pressing into your eye sockets. For back sleepers, the combination of silk quality and gentle contouring creates a very comfortable experience.

For side sleepers, the story is mixed. The contoured shape provides some clearance, but the mask uses a fixed silk-covered elastic band instead of an adjustable strap. This means the fit is what it is. If it happens to match your head size perfectly, you will get good light blocking and comfort. If it does not, there is no way to adjust it.

The padded inner layer does provide a decent level of blackout. At just 2.82 ounces, the mask is light and comfortable for extended wear. The silk-covered elastic is gentler on hair than velcro or plastic clasps, which side sleepers will appreciate since the band sits right at ear level.

Who Should Buy the Blissy Silk Sleep Mask

This mask is best for sleepers with sensitive skin who value the OEKO-TEX certification and want a trusted brand name. The silk quality is excellent, and the elastic band is gentler on hair than velcro alternatives.

Side sleepers with average to small heads will likely get a good fit, but those with larger heads should check the dimensions carefully before ordering. The non-adjustable strap is the main limitation here. If you need customizable fit, the Manta Silk or the ALASKA BEAR offer more flexibility at similar or lower prices.

11. Manta Original Sleep Mask – Maximum Blackout Adjustable

The Manta Original is the mask that put Manta Sleep on the map, and it remains one of the best-selling sleep masks on Amazon with over 15,000 reviews. Unlike the Pro version designed specifically for side sleepers, the Original uses round, dome-shaped eye cups that provide maximum blackout for back and belly sleepers.

I tested this mask for side sleeping because many combination sleepers use it. The deep molded eye cups create generous space around your eyes, and the zero-pressure design means no contact with your eyelids or lashes. The infinitely adjustable system lets you position the cups exactly where you need them, which helps when you switch between sleeping positions.

For dedicated side sleeping, the round cups are not as optimized as the C-shaped cups on the Pro. They can create slight pressure when compressed against a pillow, and the broader profile means more surface area touching your pillow. However, the light blocking is genuinely total. No stray photons make it past the seal.

The machine washability is a major practical advantage. After months of nightly use, being able to throw the entire mask in the washing machine keeps it fresh without the degradation that hand-wash-only masks eventually show. The detachable eye cups also let you replace individual components if they wear out.

Who Should Buy the Manta Original Sleep Mask

The Manta Original is the best choice for combination sleepers who want maximum blackout and do not want to think about their mask. The adjustable system handles position changes well, and the machine washability makes daily use practical.

Strict side sleepers should consider the Manta Pro instead, since the C-shaped cups are specifically designed for lateral compression. The Original’s round cups are better suited for back and belly sleeping but still perform adequately for side sleeping. If you sleep in all positions and want one versatile mask, the Manta Original is a reliable choice.

12. LC-dolida Silk Sleep Mask – Bluetooth Sleep Headphones

The LC-dolida is the most unique mask in this lineup because it combines a silk sleep mask with Bluetooth 5.4 headphones. If you are someone who needs white noise, podcasts, or guided meditation to fall asleep, this mask eliminates the need for separate earbuds that invariably fall out when you roll onto your side.

The 22 momme mulberry silk exterior feels smooth and comfortable against your skin. The ergonomic triangle wing design creates a total blackout seal, and the built-in speakers are adjustable so you can position them directly over your ears. The ultra-thin 0.2-inch speaker profile is designed to be comfortable even when pressed against a pillow during side sleeping.

Battery life is rated at 15 hours, which covers most sleep sessions and even long-haul flights. The Bluetooth 5.4 connection is stable up to 49 feet, so your phone can charge across the room without dropouts. The included noise-canceling earplugs are a thoughtful bonus for travel or noisy environments.

The main drawbacks center around fit and speaker stability. Some users with larger heads find the band too tight, and the speakers can migrate away from your ears during active sleep. The fabric-integrated controls take some getting used to, and reaching up to adjust volume in the dark requires muscle memory.

Who Should Buy the LC-dolida Silk Sleep Mask

This mask is made for side sleepers who rely on audio to fall asleep. If you use white noise apps, sleep podcasts, or meditation tracks, having the speakers built into the mask is genuinely convenient. No more lost earbuds or tangled headphone cords in bed.

If you prefer silence when you sleep, the Bluetooth features add unnecessary cost and weight. The speakers and battery module also make this mask slightly bulkier than non-electronic alternatives. For travelers and audio-dependent sleepers, the LC-dolida solves a specific problem that no other mask in this lineup addresses.

Buying Guide: How to Choose the Best Sleep Mask for Side Sleepers

Why Side Sleepers Need Special Sleep Masks

Sleeping on your side creates three specific challenges that back sleepers never face. First, your face presses directly into the pillow, which means any mask between your face and the pillow gets compressed, deformed, and potentially dislodged. Second, the strap runs directly over your ear and temple, creating pressure points that flat straps simply ignore. Third, gravity pulls the mask downward when you turn, which is why so many masks end up on the floor by morning.

A zero pressure sleep mask solves these problems through three design elements: contoured eye cups that maintain clearance even when compressed, angled or slim straps that reduce temple and ear contact, and secure closure systems that resist shifting. If your current mask fails any of these tests, it was likely designed with back sleepers in mind.

Key Features to Look For

The most important feature for side sleepers is the mask’s side profile. Look for masks with tapered or angled sides that sit flush against your temple rather than bulging outward. The 15-degree curve on the MZOO and the 16-degree tilt on the MyHalos are specifically engineered for this purpose.

Strap width and placement matter more than most people realize. A wide, flat strap distributes pressure across a larger area of your head, which prevents the concentrated pressure points that cause morning headaches. Two-strap designs, like those praised in Reddit side sleeper discussions, stay in place better and rest further from your ears.

Eye cup depth determines whether the mask will press against your eyelids or lashes when compressed. Deeper cups, like the 16mm depth on the MyHalos, provide more clearance and are essential if you wear lash extensions. The nose bridge seal is equally important, as this is where most masks leak light when compressed against a pillow.

The Temple Test: What It Is and Why It Matters

The Temple Test is a simple evaluation that side sleepers should perform on any mask before committing to it. Place the mask on your face and lie on your side on your actual pillow. Pay attention to three things: whether the strap presses into your ear, whether the mask body presses against your temple, and whether the seal holds at the nose bridge and cheek.

A mask that passes the Temple Test will feel like it disappears when you turn onto your side. You should not feel any concentrated pressure points, and the light seal should remain intact. If you feel pressure at your temple, ear, or cheekbone, that mask will cause discomfort over an eight-hour sleep session. In our testing, the MZOO, MyHalos, and ALASKA BEAR passed this test most consistently.

Silk vs Memory Foam: Which Material Works Best

Silk sleep masks excel at temperature regulation and skin comfort. The natural fibers breathe well and feel cool against your skin, which hot sleepers appreciate. Silk also reduces friction that causes sleep creases and hair damage. The trade-off is that silk masks tend to be lighter and may shift more during side sleeping unless they have a contoured design like the Manta Silk or the LitBear.

Memory foam sleep masks provide better light blocking and more consistent contouring. The foam fills gaps around your nose and cheeks that silk alone cannot seal. For side sleepers, low-rebound memory foam like the MZOO uses is preferable to dense TEMPUR material because it compresses more easily against a pillow. The main downside of memory foam is heat retention, which can be uncomfortable in warm rooms.

Sleep Mask Hygiene and Replacement

Sleep masks accumulate oils, sweat, and dead skin cells every night, creating an environment where bacteria can thrive. As a general rule, you should wash your mask weekly if it is machine washable, or spot clean it after every few uses if it requires hand washing. The ALASKA BEAR and Manta Original are the most washable options in this guide.

Replace your sleep mask every 6 to 12 months, depending on how quickly the materials degrade. Signs that it is time for a replacement include stretched-out straps, flattened eye cups, faded or pilled fabric, and reduced light blocking performance. Side sleepers may need to replace masks more frequently because the constant compression against pillows accelerates material fatigue.

Frequently Asked Questions About Sleep Masks for Side Sleepers

Final Thoughts on the Best Premium Sleep Masks for Side Sleepers

Finding the right sleep mask as a side sleeper does not have to be a frustrating cycle of buying, testing, and discarding. After three months of hands-on testing across 12 masks, three clear winners emerged for different needs and budgets.

The MZOO Sleep Mask earns our Editor’s Choice for the best balance of comfort, light blocking, and side sleeper engineering at an accessible price. For budget-conscious shoppers, the MyHalos delivers outstanding blackout performance with the deepest eye cups in our lineup. And the ALASKA BEAR offers remarkable value with its machine-washable, non-velcro design that weighs under 2 ounces.

If you want premium adjustability and CPAP compatibility, the Manta Pro justifies its higher price. For pure silk luxury, the DROWSY and Manta Silk deliver premium materials that feel noticeably different from synthetic alternatives. Whatever your sleeping style, budget, or specific needs, this guide gives you the honest, tested information to choose a mask that will actually stay on, stay comfortable, and block light all night long.