Sea To Summit Ether Light XT Insulated Air and XT Extreme Sleeping Pads Review
June 30th, 2025
Home > Gear Reviews > Camping
Our verdict
The Sea to Summit Ether Light XT Insulated Air sleeping pad is one of the best sleeping pads for people who want one pad for backpacking and camping. You may notice its thickness listed at 4”—almost twice that of every other pad we considered. It's comfortable enough for car camping, easy to use, of quality construction, and insulated enough to work for folks who only want to own one inflatable pad for camping and backpacking.
Treeline Review writer Micah Leinbach wrote, "It’s rare that I open a new piece of gear and have a ‘“wow’ moment, but the Sea To Summit Ether Light XT Extreme made it happen."
Micah Leinbach tested the Ether Light XT Extreme. Our writer Amanda Jameson also tested this pad in the women's Ether Light XT Insulated for our Best Backpacking Sleeping Pads guide. Our editor Liz Thomas tested the unisex Ether Light XT Insulated Air both on the ground and on a camping cot. Treeline online editor Naomi Hudetz tested the mummy version on the Western Wildlands bikepacking route.
True, other sleeping pads have a higher R-rating or weigh less. With all of that said, that extra weight makes the Ether Light Insulated more comfortable, and comfort is essential for a good night’s rest and a better day’s hike.
Whether you're trying to limit gear spending or have limited space in an apartment, the Sea to Summit Ether Light XT and XT Extreme are the rare gear items that span car camping and backpacking without compromise.
We create reader-supported, objective gear reviews independently selected by our editors. This story may contain affiliate links, which help fund our website. When you click on the links to purchase gear, we may get a commission — without costing you an extra cent. Thank you for supporting our work and mission of outdoor coverage for every body! Learn more.
Specs
R-Value (unisex Ether Light XT Insulated Air): 3.2
R-Value (women’s Ether Light XT Insulated Air): 3.5
R-Value (unisex Ether Light XT Extreme): 6.2
Seasons: 3 to 4
Thickness: 4”
Shape: mummy
Weight: 16.6 to 25.4 oz (excluding pump sack)
Inflation: Airstream Pumpsack
Lengths: 66”, 72”
Fabric: 30D / 40 D nylon
Insulation: Thermolite
Repair kit: included
Pillowlock system: included
Comparison table
| SLEEPING PAD | WEIGHT (ounces) | PUMP SACK? | R-VALUE | THICKNESS (inches) | PACKED SIZE (inches) | LENGTHS (inches) | WARRANTY |
|---|---|---|---|---|---|---|---|
| Sea to Summit Ether Light XT Insulated Air Sleeping Pad (unisex) | 16.6 or 17.3 oz | Y | 3.2 | 4.0 | 9.5 x 4.5 | 66, 72 | Lifetime guarantee |
| Sea to Summit Ether Light XT Insulated Air Sleeping Pad (women's) | 17.5 or 21.2 oz | Y | 3.5 | 4.0 | 4.3 x 9.4 or 4.7 x 11 | 66, 72 | Lifetime guarantee |
| Sea to Summit Ether Light XT Extreme Sleeping Pad (unisex) | 25.4 oz | Y | 6.2 | 4.0 | 6.9 x 9.4 | 72 | Lifetime guarantee |
| Sea to Summit Ultralight Insulated Air Sleeping Pad (Unisex) | 12.3 to 21 oz | Y | 3.1 | 2.0 | 9 x 4 | 50, 66, 72, 78 | Lifetime guarantee |
| Sea to Summit Ultralight Air Insulated (Women's) | 17 to 21 oz | Y | 3.5 | 2.0 | 9 x 3.75 | 66, 72 | Lifetime guarantee |
Features
A one-way valve keeps all your hard work—the easiest inflating experience I’ve had.
Valve
The Ether Light XT Insulated Air’s single inflation and deflation valve is technically two valves layered on top of each other. If you open both valves, you’re deflating the air pad; the top one is sealed for easier inflating. If the pump sack doesn’t fit, you’ve got both of them open.
Our writer Amanda was ambivalent about the stiffness of the valve–it seemed sturdy and airtight. However, with the wrangling required to get it open, there’s some concern about the integrity of the fabric around the valve with long-term use. This might not be the case with a twist-type valve.
Naomi liked the fine tune button on the valve. She inflates the pad to the max, then uses the fine tune button to get it just right – not too firm, not too soft. (She has a theory that letting out just a little bit of air leads to fewer punctures.)
Inflation pump sack
Even before a night of rest on the pad, Amanda really liked that the stuff sack has an attached pump sack instead of the extra pump sack that comes with some models like the Therm-A-Rest Neoair XTherm NXT. Amanda gets a little lightheaded after filling a sleeping pad by mouth; while the stuff sack says you can fill the pad with one breath, they managed to fill it in about 2.5 breaths.
Amanda also feels like the pump sack makes inflation a lot less awkward. Positioning your face over the valve to get it fully inflated requires some odd body-to-pad positioning that isn’t ideal on a windy day. With that being said, they were pleasantly surprised by how easy it was to adjust and fine-tune the inflation. Pressing down on the orange seal with the inflation valve open didn’t let out too much air at once, which is excellent for folks who want a specific level of inflation.
Air Sprung Cells
Most modern pads have some sort of texturing on the surface to capture heat. Unfortunately, those long, straight seams can decrease comfort. By contrast, the smaller dimples on the Ether Light accomplish the insulating effect without sacrificing comfort.
This design also helped side sleeping, as the dimples more comfortably nestled hips relative to a long seam. All of our testers (campers of varying shapes and sizes sampled the pads) felt it was the most comfortable of our more technical camping pads.
The Ether Light inflates to reveal small dimples, that serve both as insulating pockets and friction to keep you on the pad overnight.
Sea to Summit calls this technology Air Sprung cells. The brand says this is designed to mimic springs on a sprung mattress. Each cell is an interconnected chamber. Sea to Summit makes this Air Sprung technology in multiple sizes and the Ultralight Insulated Air uses medium resolution cells for the lightest and smallest pack volume to appeal to backpackers.
Pillow compatibility
The graphics in the upper left of the inflated photo show a placeholder for a pillow, a unique feature.
Rare among the sleeping pads we tested, the Sea to Summit Ether Light has graphics that indicate where you can insert your backpacking pillow. Often when brands do this, it locks you into that brand's accessory, which can be a bummer. But in our testing, Sea to Summit dominates in the inflatable pillow world, winning multiple awards in our Best Backpacking Pillows guide and offering multiple options in size and weight from ultralight to luxurious. This gives you options as you decide which pillow to use and the placeholder for the pillow means it won't move around at night.
Versatility
While it’s heavy for backpacking—17.3 oz for the sleeping pad alone and 19.4 oz for the pad and stuff sack—it’s an excellent option for 3-season camping if you run a little warmer. That's why it is the one pad you'll find in both our Best Backpacking Sleeping Pads and Best Camping Sleeping Mattresses guides.
Insulation and options
Should you need a little extra insulation, it’s also available in a winter edition called the Ether Light XT Extreme Insulated, which has an R-value of 6.2. We tested both versions.
Packability
The Ether Light XT is lightweight and packable enough for backpacking. It's also among the most insulated, with a 6.2 R-value, making it one we’d recommend for camping and backpacking in cooler temperatures.
Performance in the Field
Ease of use
Keep rolling until the air inflates the sack.
Unboxing the Etherlight felt like opening an Apple product–elegant, clean, and with clear instructions all the way from start to finish.
Even without instructions, the Ether Light sleeping pad is intuitive, but it was nice to have a guide for using the built-in “air stream pump sack.” While pump sacks are not uncommon in inflatable pads these days, this one is integrated right into the stuff sack so as not to be forgotten.
It also helped me fill the camping pad up with four breaths, a welcome relief from other pad models. Often, we have to blow up a camping mat with so many breaths that I get light-headed. This has the added benefit of keeping moisture out of the padded interior, extending the life of the pad.
Comfort
We found that the Ether Light XT Insulated is great for back sleepers and solid for side sleepers. Baffles on a sleeping pad often go either vertically (from head to foot, which can be less comfortable for side sleepers due to uncomfortable weight distribution and bottoming out) or horizontally (side to side). But, the baffles on the Ether Light Insulated run vertically through the air pad. This evens out weight distribution nicely for side sleepers and back sleepers alike.
Well then, why the lower ranking for side sleepers? We found that if you sleep primarily on your right side, the valve could press into your forehead. One solution is to get Sea to Summit’s Aeros pillow (sold separately) and attach the hook and loop patches that come with the Ether Light to secure it at night. If your head’s on a pillow, there’s no need to worry about the valve. Another solution is to flip the pad over and sleep on the side without the valve, but then you’re more likely to get dust and dirt into the valve, which can cause leakage. Also, this side didn’t seem nearly as warm when we flipped it.
Inflation
The Ether Light impressively inflates with just 4 breaths. You breathe into the bag, roll it up to capture the air.
We found the best way to fill the pad is to open the stuff sack as much as possible with your hands while it’s attached to the pad, then blow into it from about a foot away. Because the stuff sack and the pump sack are connected, you should always clean your pad before putting it away to avoid getting your stuff sack too dirty. Otherwise, there’s a non-zero chance that dirt and other debris could get inside your air pad, decreasing its lifespan.
Insulation
We could pretty quickly tell that the Ether Light Insulated is, in fact, an insulated pad. Our tester Amanda runs cold, and it started reflecting the heat off her body in under a minute when she was under a quilt. (In a sleeping bag, it would take a little longer for you to feel the warmth, given the extra layer between you and the pad.) She was a little surprised to hear the R-value is only 3.5; that is mid-range for an insulated sleeping pad, but it feels like a solid three-season pad.
Options
Warmth and insulation
The Ether Light is available in an Insulated model, and Extreme model. It also was available in an Air model, which is now discontinued and not easy to find). For the insulated and extreme model, it is also available in a women's Insulated and women's Extreme. We tested the Women's Insulated and the Unisex Extreme along with the unisex Insulated. The Extreme is designed for colder temperatures, with a much higher R-value (6.2 vs. 3.2 in the Insulated model and 1.2 in the Air).
The Insulated model is awesome for mild winter camping in 20F or lower weather, but for 3-season use, we prefer the Extreme model. If you sleep cold, check out the women’s version of the Extreme, which is even more insulated.
Compared with other camping mattresses, the R-value of 6.2 on the Ether Light is comparable to the Comfort Deluxe and just a bit lower than the Hest. But the Ether Light does so with significantly less weight and size.
Women-specific
The women’s version of the Sea to Summit Ether Light XT Insulated and Extreme are—like other women’s-specific pads—shorter and narrower than ungendered or men’s-specific sleeping pads.
Our tester is 6’ tall and 175 pounds with broad shoulders and hips, so the Sea to Summit Ether Light XT Insulated Women's wasn’t long enough (part of her calves were hanging off the bottom) or wide enough to be comfortable.
If you're shorter or narrower, regardless of gender, this specific pad might be great for you; it also comes in a long size, which brings the length to 6’. But, if you’re bigger or more restless at night, we recommend the "ungendered" version.
Shape options
The Ether Light XT Insulated is available in mummy shape and rectangular shape, so you can decide which would be more comfortable based on whether you intend to camp more or backpack more.
Should I buy the Sea to Summit Ether Light?
Buy if you want one, high-quality pad for backpacking and camping.
One downside of this model is the price—though it is comparable to many of the other backpacking-specific sleeping pads out there. So if you plan to camp and backpack and only get one pad, the price is not bad.
The Ether Light XT Extreme is a high-quality performance sleeping pad with some of the best design features out there. It is a great option for a sleeping pad, especially if you want a comfortable camping pad that is also something light enough to backpack with.
Skip if you want an ultralight backpacking sleeping pad, or are looking for a budget option.
It’s not the lightest sleeping pad out there; weighing 25 ounces, the regular model is tolerable for all but the most ultralight backpackers. If you're backpacking and looking for something lighter, our Best Backpacking Sleeping Pads guide specializes in sub-20 oz sleeping pads.
Where to buy
The Sea to Summit Ether Light XT and Ether Light XT Extreme are popular gear items, so you have options when it comes to retailers. Here are some of the pros of the retailers.
REI
Pros: 100% satisfaction policy for 1 year; 10% dividend for members.
Amazon
Pros: Free 2-day shipping with Amazon Prime membership
Backcountry
Pros: Frequent sales for Expedition Perks members (free to join), fast shipping, Gearhead chat customer service is excellent
View at Backcountry button
Similar models to consider
Therm-a-Rest NeoLoft
R-value: 7
Thickness: 4.25"
Weight (lbs): 24 oz (regular)
Inflation: Self-inflating
Lengths: 77", 80"
The Therm-a-Rest NeoLoft was released recently and has become our new winner for Best Backpacking - Camping Pad Hybrid for campers who want one sleeping pad that can do it all.
It's similar in thickness, loft, and packability as the Sea to Summit Ether Light XT. Both pads are just as thick as camping mattresses that weigh twice as much, yet pack down to the size of a Nalgene.
The major differences we see is that the NeoLoft has a higher R-value at 7, compared the Ether Light XT Extreme's 6.2. Additionally, the NeoLoft is 24 oz vs. the Ether Light XT Extreme's 30.7 oz (assuming both are the 6-foot length). The NeoLoft also has a softer face fabric.
The other major difference is price. You can find the Ether Light XT Extreme on sale for nearly half the price of the NeoLoft. So if you're considering a NeoLoft and balked at the price, the Ether Light XT Extreme is an excellent choice.
R-Value: 7.3 (rated to below -40F)
Thickness: 3”
Weight: 15.5 oz (6-foot length)
Inflation: 25-40 breaths or comes with Pumpsack
Lengths: 66”, 72”
The NeoAir XTherm is the most similar to the Sea to Summit Ether Light XT Extreme pad. However, it is not as thick. The NeoAir weighs less than the Ether Light XT Extreme. The NeoAir XTherm has horizontal baffles and uses a different WingLock Valve system with an inflation pumpsack that is larger than the Ether Light's, but can be used as a stuff sack for other items, too. We prefer the dispersed baffle system on the Sea to Summit Ether Light, but recognize it comes with a weight penalty
R-Value: 3.1
Thickness: 2”
Weight: 16.9 oz (6-foot length)
Inflation: 3 breaths or comes with Pumpsack
Lengths: 50”, 66”, 72”, 78”
What we liked: comfortable for side sleepers, efficient pumpsack system
What we didn't like: heavy, less durable
The Sea to Summit Ultralight Insulated Air uses almost a mini version of the dispersed baffle system found in the Sea to Summit Ether Light. Both are dispersed instead of horizontal or vertical. However, the Sea to Summit is only 2 inches tall compared to the Ether Light's 4 inches. We've bottomed out on the Air, especially while side sleeping. Additionally, it is not that much lighter than the Etherlight at 16.9 oz, just 0.4 oz less. It also has a lower R-value (0.1 less).
Why you should trust us
Micah Leinbach
I run BOAT (the Bus for Outdoor Access & Teaching), a non-profit focused on helping make it easier for people to get out on camping trips. As a guide and program administrator for the last decade, my teams and I have rolled out, rolled up, rolled around on, blown up, patched, and (of course) slept on hundreds of camp pads.
Sleeping pads have kept me warm and separated from ice shelves I’ve carved into beds in quinzhees, stopped me from slipping onto cactus-infested desert rock faces, and in one case, kept me just a few critical inches above a flash flood.
I’ve used a camping mattress to get comfortable nights of sleep in cars, tents, hammocks, and right out on the ground. I bring that experience to my review here.
I’m not sponsored by any of these companies, nor am I an ambassador. But I’ve purchased dozens of pads for different ages, groups, areas, and activities — and I’m happy to share what I can!
This review is unbiased, and we do this to help you find the best camping mattresses for the price. Treeline Review doesn’t accept sponsored content, native advertising, or paid reviews.
Amanda Jameson
I’m Amanda or Zuul to folks on long-distance backpacking trails. (That’s my trail name, as I’m a bit of a nerd.) I write on backpacking gear, so you might have seen my pieces on Rain Jackets, Water Filters, Backpacking Tents, and/or Trekking Poles before.
I’ve also written about going stoveless (and my Pacific Crest Trail thru-hike) for Backpacker Magazine, and about being outside for Griots Republic.
I’ve got right around 3500 miles under my feet, and I walked 3300 of those miles solo, beholden to nothing but the whims of nature and my on-again-off-again hiker hunger. Between those miles and a year as a Subaru/Leave No Trace Traveling Trainer, I’ve spent nearly a year of my life sleeping on sleeping pads-in deserts and lush valleys, on mountainsides and beachsides.
I’m a Leave No Trace Master Educator, and am a former board of the American Long Distance Hiking Association-West. I also run the blog Brown Girl on the National Scenic Trail.
You can see all of Amanda’s Treeline Review stories on their author page.
Naomi Hudetz
Naomi Hudetz is co-founder and director of analytics and digital innovation and leads business strategy and revenue operations for Treeline Review. She brings decades of private sector experience in project management, budget and pricing projection, and long-term business vision, strategy, and goals.
Naomi left her corporate career to pursue her passion for the outdoors. She received the Triple Crown award for hiking for completing the Appalachian Trail, Pacific Crest, and Continental Divide Trails and has hiked numerous other distance routes including the Great Divide Trail across the Canadian Rockies (twice), Grand Enchantment Trail, Pacific Northwest Trail, the Arizona Trail, (most of) the Idaho Centennial Trail, the first known thru-hike of the Blue Mountains Trail, and the Oregon Desert Trail. She recently bikepacked the Great Divide Mountain Bike Route.
She previously served as Treasurer of the American Long Distance Hiking Association-West, and is currently on the board of the Continental Divide Trail Coalition. She’s based in White Salmon, Washington.
Liz Thomas
I’ve backpacked over 20,000 miles and have at least 1,000 nights sleeping outdoors. On most of these overnight trips, I’ve cooked dinner on backpacking stoves. When I wake up in the morning in the backcountry, I’ll boil up some hot coffee. On chilly days, I’ll make hot lunch.
I’ve written about outdoor gear for numerous publications, including as contributing editor at Backpacker Magazine and the New York Times’ product review site, Wirecutter. I’m the author of the National Outdoor Book Award winning Long Trails Mastering the Art of the Thru-hike. My book has extensive gear and nutrition chapters--both of which address different kinds of backpacking stoves. I regularly book speaking gigs with outdoor clubs, non-profits, and colleges and universities to talk about backpacking and lead gear panels. I’m also Editor-in-Chief here at Treeline Review and oversee all of our outdoor gear stories.
You can read more about me at www.eathomas.com or at her author page.
