This is an engine alignment bar tool for MerCruiser sterndrives. This engine Alignment Tool is for MerCruiser Sterndrives including Pre-Alpha "R", Alpha One "MR", Generation II, all Bravo's, Volvo SX and OMC Comba. P/N 91-805475A1 which used to be P/N 91-57797A3. Works on Alpha One, Pre Alpha, Gen 2, "R", Bravo, All Cobra Sterndrives, Volvo SX, All #1 Drives, 1, 1A,1B, 1C. Yours seems to be the exact one in the ebay link, which is Whoya Products P/N 91-805475A1. MBS mfg also makes this tool. The link for their site is provided below as well.

This is an engine alignment bar tool for MerCruiser sterndrives. This engine Alignment Tool is for MerCruiser Sterndrives including Pre-Alpha "R", Alpha One "MR", Generation II, all Bravo's, Volvo SX and OMC Comba. P/N 91-805475A1 which used to be P/N 91-57797A3. Works on Alpha One, Pre Alpha, Gen 2, "R", Bravo, All Cobra Sterndrives, Volvo SX, All #1 Drives, 1, 1A,1B, 1C. Yours seems to be the exact one in the ebay link, which is Whoya Products P/N 91-805475A1. MBS mfg also makes this tool. The link for their site is provided below as well.

References:

https://www.ebay.com/itm/Boat-Engine-Drive-Alignment-Tool-For-Mercruiser-P-N-...

https://www.amazon.com/MAREEYA-SHOP-Mercruiser-91-805475A1-91-57797A3/dp/B07T...

https://www.amazon.com/MBS-Mfg-Alignment-Mercruiser-91-805475A1/dp/B07C6JP21M

http://mbsmfg.com/marine-engine-alignment-tool/