The fill power of goose down is an indicator of two important features: warmth-to-weight ratio and compressibility, both critical to retain warmth and furnish comfort. True fill power is measured by placing one ounce of goose down in a graduated cylinder and measuring the volume the down occupies in cubic inches. The North Face® products are insulated with exclusive, high-fill power goose down ranging from 550 to 900 fill, which represents the highest quality down commercially available.
