Paws down, the toughest and softest ToughChew fabric we've ever created. Developed exclusively by Orvis, the cover system incorporates two layers: an outer fabric engineered in a full ripstop weave from incredibly tough and durable 1,000-denier nylon, and an inner layer made of rugged 840-denier nylon. The zipper is constructed of solid brass for added strength and durability. As tough as this fabric is, it's also luxuriously soft, with a silky nylon microfiber surface that your dog will love. All of these features add up to a cover so tough, we'll refund your money if your dog chews through it. No questions asked. Washable. Imported.