Review: Sea-to-Summit Ultralight XR Insulated Sleeping Pad
The Sea-to-Summit Ultralight XR Insulated sleeping pad is designed for ultralight backpackers who prioritize low weight without sacrificing comfort or warmth. It adds extra padding and R-value compared with their uninsulated Ultralight pads while keeping packability small. For thru-hikers, ultralighters, and anyone who needs to shave ounces without sleeping on a thin foam pad, the XR aims to strike a practical balance.
- Weight tested: 14.6 oz / 415g
- Gender: Unisex
- R-Value: 3.6
- Pad thickness: 2.6 inches
- Insulated: Synthetic
- Fabric: Hybrid 30/40-denier nylon
- Dimensions: Regular: 72 x 21.7 x 2.6 (short 66″ and long 78″ models also available)
- Packed size: 3.9 x 7.5 inches
- Inflation sack: Included
- Pros: Air Sprung Cells provide better stability and comfort, compact pack size and reliable valves, robust fabric exterior
- Cons: Price relative to non-insulated pads
Comfort and construction
One of the pad’s strongest selling points is its weight-to-comfort ratio. Sea-to-Summit uses its proprietary Air Sprung Cells construction, a grid of small air chambers that flex independently, giving the XR a more stable, mattress-like feel compared to plain tube-style inflatable pads.
The extra insulation adds loft, slightly firmer support, and conforms better to the body, reducing pressure points at the hips and shoulders. The pad’s durable and robust 30/40D nylon fabric has a soft, textured finish that feels more pleasant against bare skin, and its seams and welds are well executed. At 2.6″ thick, I found that I could kneel on the pad without bottoming out while packing my gear inside my tent in the morning.
Insulation and warmth
The XR’s insulating layer brings a meaningful jump in warmth compared with Sea-to-Summit’s uninsulated Ultralight models. Rated around R-Value 3.6, it’s well-suited to three-season use.
Inflation, valves, and convenience
Sea-to-Summit’s valves are low-profile and reliable. Inflation is easy and quick with an inflator sack (recommended to avoid moisture buildup inside). Deflation and packing are straightforward: open the valve, press the pad flat, fold along the pad’s prescored lines, and roll to expel air. The pad holds air overnight without noticeable seepage, and small adjustments to firmness are simple.
Durability and field repair
Fabric and welding feel robust for an ultralight product. The included repair patch and user instructions are standard. On abrasive ground or splinter-prone lean-to floors, a tyvek groundsheet can extend the pad’s life. Sea-to-Summit’s customer service for warranty issues has a solid reputation. I know because they promptly replaced a leaky pad I had once.
Fit and sizing
The XR comes in multiple lengths and widths; choose based on your height and sleeping position. The regular width is snug but comfortable for single sleepers, while side-sleepers might prefer the wide model. A short 66″ model is ideal for smaller-statured individuals or ultralight backpacking junkies who want to carry the lightest weight model (13.8 oz / 390 g).
Comparable Ultralight Sleeping Pads
| Make / Model | Type | Length | R-Value | Weight (oz) |
| NEMO Tensor Elite | Air | 63" | 2.4 | 7.6 |
| NEMO Switchback | Foam | 51" | 2 | 10.5 |
| Gossamer Gear Torso Pad | Foam | 30" | NA | 2.8 |
| S2S UL XR | Air | 66.1" | 3.6 | 13.8 |
| S2S UL Insulated Air | Air | 50" | 3.1 | 12.3 |
| S2S Ether Light XR | Air | 66" | 4.1 | 15.7 |
| Thermarest Xlite Neoair NXT | Air | 66" | 4.5 | 11.5 |
| Thermarest Zlite Sol | Foam | 51" | 2 | 10 |
| Exped Ultra 3R | Air | 64.2" | 3.2 | 13.9 |
| Klymit Static V Short | Air | 50" | 1.3 | 14 |
The Bottom Line
The Sea-to-Summit Ultralight XR Insulated sleeping pad blends livable warmth, real comfort, and packability into one refined package. For backpackers who want better sleep on the trail without carrying traditional heavy insulated pads, the XR is a smart, well-executed choice. It’s particularly appealing to ultralight hikers who sleep on their side or change positions during the night and want more comfort than a folding foam pad provides.
Sea-to-Summit donated a pad for review.
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I bought the Sea to Summit Ether Light XR based on your strong recommendation a few years ago. What I found is that the air-sprung cell technology was both the pad’s greatest strength but also its greatest weakness. The air-sprung cells do indeed make the pad significantly more comfortable than say a Neo-Air. However, on the Ether Light, after about 50 nights of use, the pad would fail where the baffles for these cells are welded to the top fabric of the pad. While Sea to Summit was great about warranty replacement, it happened on three pads in a row for me. The last pad I received was a 2022 model. I eventually gave up and bought a Nemo Tensor.
If the process and materials are the same for this pad, as they appear to be, I cannot recommend this pad for anyone but the occasional backpacker.
huh – haven’t had any problem with my 5 year old ether light. Actually – the XR is the new model, only out this year.
My Nemo Zor blew baffles last month after about 12 yrs of use. I think I’m set on this one. It seems like an upgrade vs my old r 2.4 and 3/4 inch Nemo at about the same weight. Does the weight include th pump sack? Can it be inflated without the pump sack? I’m hoping it comes to more retailers. Ie Backcountry. I want to use my coupon and gift card.
the weight includes the pump sack. it can be inflated without the pump sack, by mouth, or any of the gazillion electronic pumps out there these days. It only takes about the 5-6 bags of air using the pump sack which makes it hardly worth carrying extra.
It’s a thicker, lighter and warmer iteration of the S2S Ultralight Insulated Air Pad. I had the last gen version which is only 2″thick and that’s too spartan even for me. It’s also a tad heavy for what it is. This new XR looks much more inviting.
I’ve also had a thinner UL version in the past – can’t remember if it was insulated or not – but like I said, I could kneel on this new one while packing my tent the next morning and not bottom out on the knees which I did in the past.
The S2S’s extra 1.7 inches width at the head end over other regular sized air mats might not seem like much, but I find it makes rolling off the sides far less likely. Even though he XR is 2 oz heavier than same size NeoAir X-Lite, the S2S is probably more durable. I really like the way the air sprung cell pads inflate and deflate so quickly. Darn, now I wish I hadn’t used my REI discount on shoe inserts.
Return the rei pad. They’ll let you reuse the coupon.
How does the Sea to Summit XR compare to the Zen Bivy Ultra light pad? I can look up the features and specs for both but I cannot see a Zen Bivy in person. Has anyone (side sleeper) compared the comfort of these two pads? On my old Thermorest Neo (first generation) I feel like I am going to roll off of it so I end up deflating it slightly. I’m concerned with this problem and I am thinking I should go to the wider 25″ pad. Does the waffle type air cell construction solve this issue or should I go wider?
I think the real comparison you want to make is the S2S Etherlight Insulated XR and the Zen Bivy Ultra. As for partial deflation – I do this regularly because I like a softer pad. Not much, but its a perfectly ok thing to do. When it comes to comfort – these dimples make a huge fifference compared to your old Neo, but truth be told, I think that 1st generation Neo was more comfortable than all the others that came after it.