Thermarest RidgeRest SOLite Regular One of the pieces of technology in the NeoAir that makes it so popular is its inner shhet of heat reflective material so Thermarest have added the same warmth-boosting alumized surface to this lightweight mattress. This surface treatment also increases durability all around and boosts performance taking the Ridgerest into the four season area for those seeking the ultimate in go-anywhere, sleep-on-anything comfort. The Ridgerest has one silver surface and one green, you sleep on the silver side this very effectively reflects heat back to you and cold away from you back to the ground. The added adavantage is its puncture proof. Features... Dimensions: 51cm x 183cm Thickness: 1.5cm Compressed dimensions: 51cm x 20cm R-Value: 2.8 Weight: 400g