V-pulley , European Standard : V-belt pulley for taper bushes: SPZ,SPA,SPB,SPC ,up to 10 grooves American standard 3V V- pulley : 1. European Standard : V-belt pulley for taper bushes: SPZ,SPA,SPB,SPC ,up to 10 grooves 2. American Standard : Sheaves for taperbushes and QD bushes : 3V,5V,8V 3. Bore : pilot bore,finish bore, taper bore , bore for QD bush V Belt pulley