This is a new MerCruiser Hinge Pin Tool (OEM 91-78310) This tool is used on the hinge pin bolt and separates the housing from the gimbal ring. This tool will work on MerCruiser Sterndrives: Alpha One, Alpha One Generation Two, Bravo One, Bravo Two, Bravo Three, R, MP, MC-1. ***Tool Comes with Black Oxide Coating For Years of Use***