This roller is used by air control sliding screen doors as well as glass patio doors using a narrow grooved roller. It is used in various applications by many patio door manufacturers. It is a high density polyethylene roller 1 in Dia by 7/32 in thick. It has a 1/4 in axle hole. This roller comes with a 8-32 x 3/8 in machine screw and binder post for installation into the bottom screen frame rail.