Feather and down duvet: Get extra cosy with a 13.5 tog goose feather and down duvet. Sizes: Single, Double, King or Super King. 13.5 tog: Ideal for Autumn and Winter. Goose feather and down: Filled with 85% goose feather, and 15% goose down for extra softness. Down proof cover: 100% microfibre down-proof cover made from 233-thread count percale for durability and breathability, and to ensure the filling does not move around in the night. Machine washable: Machine washable at 40 degrees, and can be tumble dried.