The Nimbus New White Duck Feather & Down duvets contain small fluffy feathers & light down clusters. Providing excellent warmth & comfort, whilst retaining the breathability necessary for a good nights sleep. They are made with a pure cotton percale 240-thread-count casing which is breathable & downproof. Guaranteed for 10 years. 15% Duck Down, 85% Duck Feather with 100% Cotton Casing