PGGT Timing Belt Pulley Bore Diameter 1/2 in For Belt Series PowerGrip GT For Belt Width 15 mm For Use With PowerGrip(R) GT2(R) Belts Material Ductile Iron Maximum Bore Diameter Not Applicable Number of Teeth 50 Outside Diameter 3.33 in Pitch 5 mm Pitch Diameter 3.133 in Bore Type Plain Face Width 0.891 in Features Built for High-Torque Low-Speed Applications Outperforms Industry Standards Superb Flexibility Finish Black Oxide For Belt Trade Size GT Hub Diameter 2 1/2 in