Double Shell 600 Hypo-Blend Medium Pillow, Our Hypodown blend is four parts white goose down and one part Syriaca clusters, a fiber from the milkweed plant, The two work hand in hand to give you the best of their natural abilities: warmth and comfort, Down clusters are the soft fluff under feathers that keep birds comfortable no matter what the climate, In order to measure nature"s performance, down is rated by two distinct values, Percent Down Cluster and Fill Power, Syriaca clusters trap and suppress allergens, Sizes: King, Ogallala down is Hungarian white goose down - the top down you can buy, Made in United States, Dimensions: 20"" H x 26 - 36"" W, SKU: OGCC116