The Sea to Summit Etherlight Mat design creates a thicker mat, without increasing overall weight. Cleverly constructed comfort for the coldest conditions. Designed with extreme conditions in mind, the unique ‘dual-density’ Thermolite insulation minimizes both internal convection and internal air movement, making the Ether Light Extreme suitable for use in very cold environments. 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. 6.2 R-Value is perfect for cold weather adventures. At four inches thick, Ether Light XT Air Sprung Cells provides a plush sleeping experience. Dual-density layers of Thermolite® insulation fill the inner space, preventing heat loss due to convection and internal air movement. Lighter, quieter, and durable 30D/40D face fabric with Sea to Summit’s liquid-extruded lamination is extremely reliable. Quick and easy inflation, deflation, and adjustment is made possible by our multi-function valve and supplied Airstream Pump/stuff sack. Anti-microbial treatment added to the TPU lamination formula prevents internal mould growth. PillowLock system prevents your Sea to Summit Aeros Pillow from slipping. Comes with a stuff sack which doubles as a pump, a repair kit with six self-adhesive patches and a spare valve insert. Rectangular Regular Wide Size is 64 Cm (25") wide by 183 Cm (72") Long Weight 950 g (2lbs 2oz) Ether Light XT Extreme Insulated Air Sleeping Mat Rectangular Regular Wide