A higher ratio of feathers to down gives this duvet a comforting, weightier warmth. The piped 240 thread count cotton cover is down-proof, so the can't escape. Stay warm and cozy while you sleep with the Natural Duck and Feather Down Duvets. The natural materials offer breathable insulation, regulating temperature and providing superior comfort. Enjoy a good night's sleep with the natural benefits of a Duck & Feather Down Duvet. - The Lyndon Company Goose Feather & Down 240 Thread Count Casing 13.5 Tog Duvet in White - Size: King