Made to fit Sleep Number beds by Select Comfort. This complete shell is for those who need to replace both the top quilted section and the bottom section. This model fits both duel chamber and single chamber beds, as there are three hose outlets at the head of the bed. The Ultra shell features the same YKK zipper (5cnu) used by Select Comfort. Not only is this shell made in the U.S.A., but all components are as well. We use only the best fabrics, foams, upholstery threads and padding. This complete shell is specifically designed to fit Select Comfort Sleep Number beds. We guarantee a snug fit, just like the original. Note: We are not affiliated with Select Comfort / Sleep Number Beds