Cast Iron 6" Single Groove Belt A Section 4L Pulley with 1-3/8" Sheave Bushing Masterdrive single groove 6" cast iron pulley/sheave with 1-3/8" H bushing for A section belt is a high-quality 2-piece pulley that measures 6" 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 style of pulley is 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 Single Groove Pulley For Use on 1-3/8" Shaft 1-3/8" Bushing Included Outside Diameter of Pulley: 6" High-Quality Cast Iron Construction Accepts: A Section / 4L Section Belts