Chicago Die Casting 1/2" Bore x 2-1/2" Diameter Single V-Groove Die Cast Pulley is designed for use with 4L or 1/2" x 11/32" belts. It features a hollow head set screw for secure attachment. This pulley is made of die cast metal for durability and long-lasting performance. It is commonly used in a variety of applications, including industrial machinery, automotive, and agricultural equipment.