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 orange model the upper fabric is Black Yarn, a specially carbon impregnated fibre that accumulates & retains heat & enhances moisture wicking making this model the warmest & lightest & gucciest. The base is a tough durable material with an anti slip printed logo design.