Sierra 18-6158M Alpha 1 Gen II Magnesium Anode Kit Sierra quality replacement magnesium anode kit for use with Mercruiser Alpha One Gen II drives. The anodes in this kit are constructed of magnesium and should only be used in freshwater applications. All Sierra aftermarket marine parts are manufactured to meet or exceed OEM requirements. For Alpha One Gen II 1991 up Interchangeable with Mercruiser Stern Drive 888755A1 888755Q01 97-888755Q03 California Residents WARNING Cancer and Reproductive H