Triple Groove Pulley Solid Steel Bushing For Use on 7/8" Shaft 7/8" Bushing Included Outside Diameter of Pulley: 6" Masterdrive triple groove 6" cast iron pulley/sheave with a 7/8" H-bushing for B section belts is a high-quality 2-piece pulley that measures 6" outside diameter and is designed to be used with an H-style bushing. The 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 making this style of pulley much more secure than a standard single-piece pulley. The bushing is made of solid steel and precision machined to ensure high quality and secure attachment to your motor/engine shaft. This pulley accepts B Section also known as 5L series belts and is 5/8" wide. This pulley will work with A Section belts A, also known as 4L; however, they will sit farther down in the groove, reducing the pulley size by 1/4" to 1/2" on average, depending on the size of the pulley. Specifications: Triple Groove Pulley Solid Steel Bushing For Use on 7/8" Shaft 7/8" Bushing Included Outside Diameter of Pulley: 6" High-Quality Cast Iron Construction Accepts: B Section / 5L Section Belts