Always a favorite of the ultralight elite, the Z Lite SOL expands upon the utralight performance of the Original Z Lite by adding our reflective ThermaCapture™ coating to capture radiant heat and increase overall warmth by nearly 15%. Factoring in the system of heat trapping dimples, the Z Lite SOL has an R-Value of 2.0, making it perfect for use on its own in warmer weather or layering under another pad for extra warmth in the cold. The proprietary foams are softer on top for extra comfort and denser on the bottom for extra durability, making the Z Lite SOL an idealclosed-cell foam pad for those in need of an ultralight, highly compact and super-reliable sleep system. Advanced Warmth:ThermaCapture™surface reflects radiant heat back to your body, amplifying the warmth of the heat-trapping dimples by 15%; use reflective side-up. Compact Design: Folding design is compact and easy to pack. Extra Durable: Virtually indestructible, the proprietary closed-cell foam provides lasting, economical comfort.