Uses a chain and a two-sprocket arrangement to make the door much easier to lift. Mounts on a 1″ diameter shaft extension fastened to the door axle. Mounts on either side of the door. Chain keeper provided.

Uses a chain and a two-sprocket arrangement to make the door much easier to lift. Mounts on a 1″ diameter shaft extension fastened to the door axle. Mounts on either side of the door. Chain keeper provided.