Ether Light XT Extreme Insulated Air Sleeping Mat

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.