A Groove Pulleys 2 Step Step-Cone Pulley 3 Step Step-Cone Pulley 4 Step Step-Cone Pulley Variable Pitch Pulleys Bushings 2 Step, Zinc Die Cast Step-Cone Pulley Item Bore Size OD OD2 F Weight SCA300-2X050 1/2 2 3 1 7/32 0.52 SCA300-2X062KW 5/8 2 3 1 7/32 0.52