Cast Iron 3.5" Dual Groove Belt B Section 5L Pulley w/ 1" Sheave Bushing Masterdrive dual groove 3.5" cast iron pulley/sheave with 1" H bushing for B section belt is a high-quality 2-piece pulley that measures 3.5" 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 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 B Section also known as 5L series belts and is 5/8" wide. Specifications: Solid Steel Bushing Dual Groove Pulley For Use on 1" Shaft 1 Bushing Included Outside Diameter of Pulley: 3.5" High-Quality Cast Iron Construction Accepts: B Section / 5L Section Belts