"This Phoenix 2 1/4in. Flat Idler Pulley Wheel with 3/8in. bore offers smooth operation, high speed performance and long life. U.S.A. Bore Diameter in. 3/8, Part Type Pulleys, Pulley Diameter in. 2 1/4, Material Type Steel, Product Style Flat idler pulley. Precision ground bearings with double seals protect against dirt and moisture for high speeds and long life"