BEST USE: Cold Weather Backpacking
WEIGHT: 1lb 9oz | 720g
PERFORMANCE: 4 Season
PACKED SIZE: 6.9 x 9.4 in | 17.5 x 24cm
Shipping & Returns
Our warehouse is actively shipping orders from 8am to 1pm MST Monday through Friday. Most orders ship in one business day, but the transit time can take up to 7 days, depending on your distance from Boulder, Colorado.
2nd Day and Next Day Air orders will ship same day if placed by 1pm MST, Monday-Friday (except holidays).
All orders are eligible for fast and easy returns within 60 days of purchase.
For more details, please check out our Help Center
The Ether Light XT Extreme is extra thick and exceptionally warm. The XT Air Sprung Cells provide four inches of stability and comfort, while dual-density layers of THERMOLITE® insulation prevent convective heat loss and internal air movement. This results in true four-season performance.
Thermolite® HL-1 is part of the family of Thermolite® materials used in Sea to Summit sleeping bags, sleeping bag liners and sleeping mats. HL-1 high loft insulation is a fiberfill constructed with a unique 3D crimp of hollow-core and solid fibers, which provides excellent lightweight warmth with superior durability. The Thermolite insulation lofts up inside the Air Sprung Cells™ of our sleeping mats to prevent convective heat loss from your warm body to the cold ground.
The Airstream™ Pumpsack is Sea to Summit's big volume mattress pump which we've now integrated into the stuff sack of every Air Sprung Cell™ mat. The clever design opens at one end to stow the air mat and the other end unfolds to become the built-in pump. The Airstream™ Pumpsack can be inflated with a single breath and takes just two or three cycles to fill our mats. Not only is it faster than inflation by mouth, but there is minimal breath condensation entering the mat and it eliminates dizziness from blowing the mat up directly by mouth. The Airstream™ Pumpsack is also compatible with Sea to Summit's smaller multifunction valve, which is now featured on the updated Aeros pillow range, along with the Air Seats.
To ensure that you will be warm when you sleep (especially when the ground is colder), it is essential to know how well your sleeping mat resists heat loss into the ground. This resistance is known as an R-Value. A laboratory-tested R-Value is the only way to measure resistance to heat loss. Sea to Summit has always provided independent lab-tested R-Values for its sleeping mats. Since January 2020 we have used the industry standard ASTM F3340-18 test to provide R-Values for our mats. There are other factors which will determine how well a sleeping mat will insulate; but the standardized ASTM R-Value test means that you can compare resistance to heat loss in sleeping pads across different brands.
Air Sprung Cells™ are the core technology used in Sea to Summit Air Mats and are the reason you will sleep more comfortably on a Sea to Summit mat than on a conventional air pad. Inspired by the springs of a modern pocket sprung mattress, dozens of interconnected chambers (called Air Sprung Cells™) perfectly support your weight and conform to your body contours. The Ether Light range uses loops of TPU material to connect the top and bottom welds. This produces a thicker cell to give you a plush sleeping experience without compromising on Sea to Summit's Air Sprung Cell comfort.
Best UseCold Weather Backpacking
Comes WithStuff sack w/ integrated pump, repair kit & Pillow Lock
FabricDurable 30D/40D nylon
Season Rating4 Season
SpecialAnti-microbial liquid-extruded TPU lamination to reduce delamination
Thickness4 in / 10 cm
|Rec. Reg Wide
Frequently Asked questions
Is this sleeping pad comfortable at this thickness?
Yes. Thickness isn't the key factor for sleeping pad comfort – the number of points of suspension is. Our air sprung cell sleeping pads support your body weight with hundreds of individually air-filled springs.
Is this sleeping pad easy to inflate?
Yes! The supplied stuff sack features an integrated Airstream Pump which will quickly and easily inflate the sleeping pad. This means no hard work and dizziness for you, and practically no condensation moisture inside the pad.
Does the sleeping pad make noise when I shift around in my sleep?
No. The reflective material (Exkin Platinum®) and the outer laminate material are both very quiet. Your tent buddy will thank you in the morning.
Is the Ether Light XT Extreme Insulated Sleeping Pad warm enough for winter conditions and four-season use?
Absolutely. The tested R-Value of 6.2 of this sleeping pad and lack of internal air movement (which reduces heat loss) makes it perfect for colder temps and four-season use.