"The Phoenix 5/8in. x 3 1/2in. 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. Pulley Diameter in. 3 1/2, Bore Diameter in. 5/8, Compatible With Outdoor power equipment, Material Type Split steel, Part Type Pulleys, Product Style V-belt pulley. Heavy-duty split steel construction 3/16in. standard shaft keyway size 2 set screws are factory inserted for strength"