ThermalCore insulation consists of multiple TRM layers that are quiet and reflect back infrared energy to the sleeper for increased insulation Extended 3 season capable, ASTM-tested R-Value of 4.1 Lighter weight and significantly reduced packed size compared to prior models Air Sprung Cell construction, 10cm | 3.9in thick for plush, stable comfort in any sleeping position XPRESS valve and pumpsack integrated into stuff sack make inflation, adjustment and deflation a breeze The Ether Light XR eases you to sleep with its 10cm of plush comfort. A long day on the trail deserves a great night’s rest with minimum effort. The Airstream pump integrated into the stuff sack and a high-airflow XPRESS valve make inflation and deflation quick and simple. Lean into the ThermalCore technology which increases insulation while keeping weight and volume low. So toss it in your pannier or backpack and head into the backcountry knowing that your sleep comfort is one less thing to worry about.