The Thermarest Z Lite SOL features a compact accordion-style shape and heat-trapping dimples. The Z Lite SOL adds our reflective ThermaCapture™ coating that helps capture radiant heat, increasing overall warmth by nearly 20%. The proprietary foams are softer on top for extra comfort and denser on the bottom for extra durability. Wherever you're headed, this mattress is the right choice for ultralight warmth, durability and comfort. Z Lite SOL Regular Sleeping Mat