21MM Belt Width; 8MM Belt Pitch; 8M-21 Poly Chain GT2 Belt Style; 31 Teeth; 23.368MM Face Width; Bushed; 84.531MM Flange OD; 77.343MM OD; 78.943MM Pitch Diam; Keyway; 12.7 To 31.75MM Bushing Bore Range; 1210 Bushing; No Minimum Plain Bore