Engine Alignment Tool for MerCruiser Sterndrives including Pre-Alpha "R", Alpha One "MR", Generation II, all Bravo's, Volvo SX and OMC Comba. This Tool is similar to P/N 91-805475A1 which used to be P/N 91-57797A3. Tool is made from high quality 1045 Steel. Proudly manufactured and assembled in the United States.