Fits for all mercruiser Alpha one, Pre Alpha, Generation 2, Bravo One, Trs outdrives will also fit for Mercury / Mariner outboards 150HP an.
The tool set are used to remove and install driveshaft housing (upper) bearing retainer nut (By U joint shaft) on #1 (1982 and earlier), R, MR, Alpha Gen 1 (1983 -1990), Alpha Generation ll (all), MC1, and all Bravo and Blackhawk units.