Chicago Die Casting 3/4" Bore x 4" Diameter Single V-Groove Die Cast Pulley is for use with 4L or 1/2" x 11/32" belts. It has a hollow head set screw and is made of zinc. The pulley has a face width of 11/16", a pitch diameter of 3-3/4", and a keyway size of 3/16" x 3/32". It includes hollow head set screws.