A goose down comforter is filled with the soft and fluffy down feathers of geese. These feathers are known for their incredible insulating properties, making goose down comforters incredibly warm and cozy. The fill power of a goose down comforter is a measure of how fluffy and insulating the down is, with higher fill power indicating a higher quality and warmer comforter. https://www.warmytummy.com/products/deluxe-silk-goose-down-comforter-2-shams