This superior Platinum Down 10.5 tog double duvet is filled with a luxurious blend of platinum duck down & feather which offers superb natural warmth without weight. The duck down fill is fluffier & lighter than feathers, which are the most effective at maintaining warmth. The feather fill duvet has a crisp & naturally breathable 100% cotton percale cover & is rated 10.5 tog in warmth, suitable for spring/autumn.