From the Manufacturer
These unique levelers are the easiest way to add an insert plate to your shop-built router table. They eliminate the need for a supporting rabbet and feature a unique bottom-mount design which includes 8 adjustable points of contact, four-corner lock-downs for stability and locating tabs for easy installation.
These unique levelers are the easiest way to add an insert plate to your shop-built router table. They eliminate the need for a supporting rabbet and feature a unique bottom-mount design which includes 8 adjustable points of contact, four-corner lock-downs for stability, and locating tabs for easy installation. Package includes 4 insert plate levelers. Designed for 3/4″ corner radius. Works with router tables up to 1-1/2″ thick