"The Phoenix 1in. 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. Pulley Diameter in. 4, Compatible With Outdoor power equipment, Bore Diameter in. 1, Material Type Split steel, Product Style V-belt pulley, Part Type Pulleys. Heavy-duty split steel construction 1/4in. standard shaft keyway size 2 set screws are factory inserted for strength"