"The Phoenix 5/8in. x 4in. V-Belt Pulley is a heavy-duty split steel pulley fabricated from solid steel stock. Replacement for lawn and garden, farm and agricultural, and industrial equipment. U.S.A. Bore Diameter in. 5/8, Part Type Pulleys, Material Type Split steel, Pulley Diameter in. 4, Product Style V-belt pulley, Compatible With Outdoor power equipment. Heavy-duty split steel construction 3/16in. standard shaft keyway size 2 set screws are factory inserted for strength"