6.5" Double Groove B Section 5L Sheave with 1" H-Style Split Taper Bushing - 2BK67HCast Iron 6. 5" Dual Groove Belt B Section 5L Pulley w 1" Sheave Bushing Masterdrive dual groove 6. 5" cast iron pulley sheave with 1" H bushing for B section belt is a high quality 2 piece pulley that measures 6. 5" outside diameter and is designed to be used with an H style bushing. This bushing inserts into the center of the pulley and slides over the shaft, as you tighten down the bolts on the H bushing it will tighten down on the shaft. This