Mercury - Magnesium Anode Kit MR & Alpha One Series Freshwater Protection 888755K02. Overview. If you spend your weekends on freshwater lakes, you know how much trust you put in your sterndrive every time you throttle up. There's a certain comfort in knowing your gear is protected, especially the parts you rarely see but rely on the most. The Mercury Marine part number 888755K02 Magnesium Anode Kit gives your MR or Alpha One drive the kind of protection that lets you relax, drift, cast, or cruis