The NeoAir XTherm Max sleeping mattress is the warmest from the Therm-A-Rest NeoAir collection and this Max version comes in a more spacious rectangular shape with all the same features as the standard XTherm. By using ThermaCapture™ Technology which is a reflective barrier to allow the mattress to capture more heat the XTherm Max provides four season warmth without the added weight or bulk associated with conventional mats. Perfect for multi-day adventures where weight and pack-size are as important as a good night's sleep, the Therm-a-Rest NeoAir XTherm Max provides excellent comfort and warmth without compromising weight and pack size. Therm-A-Rest Neoair Xtherm Max (Large) Features: Fabric 30D High Tenacity Nylon Ripstop Lightweight and Compressible New WingLock™ Valve Technology ThermaCapture™ Technology Triangular Core Matrix™ Construction Dimensions 64cm x 196cm Packed Dimensions 28cm x 11cm Triangular Core Matrix Thickness 6.4cm Relative warmth R-Value 7.2 Weight 570g Pump Sack, Stuff Sack and Repair Kit Included