These incredibly warm & comfortable slip on shoes are insulated with soft duck down for warmth & luxury. The durable fabric uppers are the same stuff Nordisk use for their sleeping bags with each colour shoe featuring a different face fabric. They are all lightweight & water resistant with an elasticated opening to keep out out drafts & stuff. On this blue model the upper fabric is 22 x 20 Denier Rip-Stop Nylon making this model very light & soft yet durable. The base is a tough durable material with an anti slip printed logo design.