Ether Light XT Insulated Air Sleeping Pad

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 create a sleep system appropriate for anticipated conditions (especially when the ground is colder), it is essential to know how well a sleeping mat resists heat loss into the ground - this resistance is known as an R-Value.

Sea to Summit has always provided independent lab-tested R-Values for its sleeping mats. We have used the industry standard ASTM F3340 test since January 2020.

Other factors determine how well a sleeping mat will insulate; but the standardized ASTM test is a good starting point for comparing performance across brands. Not all published R-Values are lab tested. Look for the 'ASTM F3340' icon - if this is not present, it is likely that the R-Value has been estimated.