Serpentine belt 865615Q02 is 2, 285mm long to fit MerCruiser 8.1S engines (2001 through 2004 with serial No. 0M025000 through 0W389999) and MerCruiser 496 Magnum engines (2001 through 2005 with serial No. 0M025000 through 0W389999) where the power steering pump has been removed. It is the same belt as installed by MerCruiser. See your owner's manual or service manual for specific applications. Replace worn or damaged belts to maintain proper function of engine systems driven by the belt. Easy to install using common tools. The Quicksilver brand is the leader in delivering uncompromising engine oils, parts and accessories to the marine industry for over 65 years. Quicksilver is the premier supplier of Mercury Marine original Equipment replacement engine parts, oils, and accessories, but also works to serve all original Equipment brands in the marine and powersports industries. It has earned a loyal following by providing the highest quality products that are tested through some of the most rigorous environments and testing procedures. No aftermarket company comes close to the level of research and design as Quicksilver; buying Quicksilver is buying performance, protection and peace of mind.