Ether Light XT Extreme Insulated Air Sleeping MatThe Ether Light XT Extreme is extra thick and exceptionally warm. The XT Air Sprung Cells provide 10 cm 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. Features 6. 2 R Value is perfect for cold weather adventures. At 10 cm thick, Ether Light XT Air Sprung Cells provides a plush sleeping experience. Dual density layers of