The Therm-A-Rest Neo Air Dream consists of a 3 inch Neo Air inflatable mattress with its Therma Capture triangular core. The mat is basically air filled, & that air is trapped in hundreds of triangular internal chambers with a reflective surface that bounces your radiant body heat back into your sleeping bag & away from the cold ground. Cold air is also reflected back to the ground so it cannot penetrate your body. This Neo Air mat is then incased in a washable nylon based and microfleece upper, giving this sleeping pad a tough base & a super comfy next to skin feel. It doesnt stop their either. Inside this comfort sleeve is an open cell foam topper that sits between the Neo Air mat & the microfleece upper for extra luxury & a great sleeping experience, whilst adding a bit more thermal efficiency. The great thing about the Dreamer is it versatility; if you were going on a basecamp trip then you can take it all in one piece, however if you were going to go on a light weight camping trip you can strip of the foam & comfort sleeve leaving you with a lighter-weight more packable sleeping mat. 4 season performance Therma Capture Technology Triangular core matrix Comfortable Versatile