Dodge Extended Pitch Sprocket, Taper Lock Type B, 6.39 in Outside Dia, #60 Chain, 25 Teeth, 11.968 in, 2-1/8 in Maximum Bore, Steel Special pitch diameter for extended pitch roller chainChain engages every other toothEffective number of teeth equals half the actual number of teethOdd number of teeth preferred to automatically balance wear on sprocketFor 1-1/2 in double pitch drive/conveyor chain