50/50 white Goose down and Feather Baffled cassette construction for an even fill with no cold spots Luxury down proof cotton casing with high thread count fabric 5 Year Guarantee Machine Washable The Downia Silver Collection white goose down and feather duvet is ideal for use in Autumn, Spring and warmer Winter months. It has a sewn through construction using a luxurious and soft 280 thread count cotton down-proof casing. 50% White Goose Down and 50% Feather.