PCGT Timing Belt Pulley For Belt Series Poly Chain GT Carbon For Belt Width 21 mm For Bushing Size 2517 For Bushing Type Taper Lock For Use With Poly Chain GT Carbon Belts Material Cast Iron Maximum Bore Diameter 2 1/2 in Minimum Bore Diameter 1/2 in Number of Teeth 67 Outside Diameter 6.875 in Pitch 8 mm Pitch Diameter 6.717 in Face Width 1.203 in Features Built for High-Torque Low-Speed Applications Outperforms Industry Standards Superb Flexibility Finish Black Oxide