Timing Belt Pulleys Bore Diameter 3/16 in For Belt Series XL For Belt Width 3/8 in For Use With 3/8 in Wide Belts Material Aluminum Maximum Bore Diameter Not Applicable Number of Teeth 12 Outside Diameter 1 in Pitch 0.2 in Pitch Diameter 0.764 in Bore Type Fixed Face Width 0.563 in Features Built for High-Torque Low-Speed Applications Outperforms Industry Standards Superb Flexibility Finish Anodized For Belt Trade Size XL Hub Diameter 1/2 in Hub Projection 1/4 in