The Therm-a-Rest Z Lite Sol Sleeping Pad is a foam mattress for lightweight backcountry adventures. The Z Lite Sol doesn't inflate, so you don't have to worry about holes or repair patches. The closed-cell foam is denser at the bottom than it is on the top, providing additional durability against rocks, sticks, and whatever else your tent may be pitched upon. The ThermaCapture; surface is where it's at, reflecting your own heat back at your body as you get some shut eye, so make sure you place the shiny silver side up. Folds up in a flash, just hook it to the sleeping pad straps on your pack in the morning and move along on the trail.