Prime-Line Products T 8758 Zipper Pile Weatherstrip for Windows & Doors, 18 ft., Grey, Owens Corning, Non-Adhesive Used on windows & doors to improve energy efficiency by sealing gaps and leaks which allow outside air to enter, and inside conditioned air to escape 1/4 in. width x 3/8 in. height x 18 ft. length Constructed of grey pile fibers Woven pile weatherseal material with zig-zagged NON-ADHESIVE backing