This extended trim tab anode fits into the anti-ventilation plate trim tab anode cavity in Mercury 9.9 hip through 15 hip (323 cc) 4-stroke Bigfoot outboards, Force 25 hip outboards (serial number 0E090400 through 0E344999) and other 2-cycle Mercury and Mariner outboards. See your owner's manual for specific application. Check for proper propeller clearance at time of installation. 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 power sports 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.