PCGT Timing Belt Pulley For Belt Series Poly Chain GT Carbon For Belt Width 12 mm For Bushing Size 1210 For Bushing Type Taper Lock For Use With Poly Chain GT Carbon Belts Material Cast Iron Maximum Bore Diameter 1 1/4 in Minimum Bore Diameter 1/2 in Number of Teeth 31 Outside Diameter 3.543 in Pitch 8 mm Pitch Diameter 3.108 in Face Width 1 in Features Built for High-Torque Low-Speed Applications Outperforms Industry Standards Superb Flexibility Finish Black Oxide