PCGT Timing Belt Pulley For Belt Series Poly Chain GT Carbon For Belt Width 20 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 37 Outside Diameter 7.167 in Pitch 14 mm Pitch Diameter 6.492 in Face Width 1.359 in Features Built for High-Torque Low-Speed Applications Outperforms Industry Standards Superb Flexibility Finish Black Oxide