PrimaLoftTM Synergy: synthetic insulation. Larger outsider air chambers keep you cradeled in the middle of the pad * I-beam construction eliminates welded seams to reduce cold spots and ensures quick inflation/deflation, consistent air flow and stability * Durable, lightweight 70D nylon diamond rip-stop top and bottom. Durable inflation valve. Internal polyurethane coating * R-Value: 4.1. Rated to 35F * 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!