The Precision Router Table Insert Plate is made from compression-molded phenolic, which is 30% stronger, and 20% more rigid than standard phenolic, meaning it starts out flat and stays flat, even when used with a large, heavy router. The plate is equipped with Level-Loc Reducing Rings that simply twist into place using an included ring wrench to lock in level and flush to easily change the size of the opening around the router bit. Three Level-Loc Rings: 25mm, 30mm for use with universal-style guide bushings and 67mm rings are included. In adition features this insert plate predrilled holes and mounting hardware to fit Triton M0F001 and TRA001 Routers.