aCast Iron 4" Dual Groove Belt A Section 4L Pulley fits 7/8" Shaft Masterdrive dual groove 4" cast iron pulley for A section belt. This cast iron pulley is designed to fit a 7/8" keyed shaft and features dual set screws to ensure a completely secure fitting. Most pulleys similar to this only have one set screw, making them less reliable in many working conditions. This pulley is designed to be used with A Belts (also known as 4L Belts). Specifications: Solid Steel Bushing Dual Groove Pulley For Use on 7/8" Shaft Outside Diameter of Pulley: 4" High-Quality Cast Iron Construction Accepts: A Section / 4L Section BeltsCast Iron 4" Dual Groove Belt A Section 4L Pulley w/ 7/8" Sheave Bushing Masterdrive dual groove 4" cast iron pulley/sheave with 7/8" H bushing for A section belt is a high-quality 2-piece pulley that measures 4" 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 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 A Section also known as 4L series belts and is 1/2" wide. Specifications: Solid Steel Bushing Dual Groove Pulley For Use on 7/8" Shaft 7/8" Bushing Included Outside Diameter of Pulley: 4" High-Quality Cast Iron Construction Accepts: A Section / 4L Section Belts