Prime-Line N 6817 Door Roller, 1-1/2 in Dia Roller, Bottom Mounting, Steel

N 6817 is an adjustable mirrored door 1-1/2 in concave or grooved nylon roller used on Cox Series 21 and 22 Door Systems. The unique design has bottom feet or brackets that fit under the door frame and fastened into place there and up the side. The 1-1/2 in nylon roller provides a smooth ride for heavy mirrored doors.