I-beam construction eliminates welded seams to reduce cold spots and ensures quick inflation/deflation, consistent air flow and stability * Alternating I-Beam construction creates smoother, more comfortable feel. Ergonomic "V" shaped air chamber design conforms to your body * Durable nylon rip-stop top and bottom. Durable Inflation valve * Internal heat reflective polyurethane coating. R-Value: 1.5 * Stuff sack and repair kit included. The repair kit is in a small pocket on the inside of the stuff sack. It"s sort of hidden, so look twice!