Engine idler pulley 8M6500024 is for use on 4.3L, 5.0L, 5.7L, 6.2L & 8.1L MerCruiser stern drive and inboard engines. This thermal resin pulley is 3" in diameter, is flat with no grooves. The pulley is made of long-lasting thermal resin. The bearing is molded into the pulley. When replacing the idler pulley, check the pulley support bushing and serpentine belt for damage or wear. Replace as necessary to help keep your engine running at its peak performance. The Quicksilver brand has been the marine industry leader in delivering premium engine lubricants, accessories and original equipment replacement parts for more than 65 years. It applies the same quality standards as a supplier of lubricants and replacement parts for many original equipment brands in the powersports industries. Quicksilver has earned a loyal following by providing the highest quality products, validated through some of the most rigorous environments and testing procedures. No aftermarket company comes close to matching the level of research and design that goes into Quicksilver products. Buying Quicksilver is buying performance, protection and peace of mind.