21MM Belt Width; 8MM Belt Pitch; 8M-21 Poly Chain GT2 Belt Style; 28 Teeth; 23.368MM Face Width; Bushed; 81.534MM Flange OD; 69.698MM OD; 71.298MM Pitch Diam; Keyway; 12.7 To 28.575MM Bushing Bore Range; 1108 Bushing; No Minimum Plain Bore