https://www.sportsmans.com/fishing-gear-supplies/downriggers-and-planer-boards/downrigger-accessories/berts-custom-tackle-fixed-mount-base-downrigger-accessory-4in/p/1554420?channel=shopping&gclid=CjwKCAjw7IeUBhBbEiwADhiEMWpTiABognM75zxKzW-UNjdlhPpTHaVECXovo1ogUrJbNMpcdJvfrBoCdgIQAvD_BwE
Says the universal mounting plates are "Pre drilled and tapped for all riggers on the market"