Alternator belt 8M0031641 is for use on 150 hp Mercury 4-stroke outboards (s/n 1B905505 and above). Reinforced for durability and long service life. Easy to install with common tools. See your owners manual or service manual for specific applications and replacement instructions. Periodic maintenance and service helps protect your investment in your engine and your boating pleasure. 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.