We would be happy to help answer your questions. RP64153 includes the mounting post, wrench, and set screw only. The slide mount is part number RP64155. It will not work on the 51589 slide bar.
The slide bar for the 57021 is round, so the mount can rotate on the bar. The bar is 3/4" in diameter.
Best regards, Jon
Date published: 2018-06-19