3/8-inch thick phenolic router plate supports any router. 2 removable rings give three different bit openings: (3-7/8, 2-5/8, 1-3/16-inch). Note: 1-3/16-inch opening is designed to hold Porter Cable style guide bushings. The steel starting guide pin allows routing curved work. The plate is approximately 9 -by-12-inch with pre-drilled table mounting holes. Includes magnets and adjusting screws for securing and leveling the plate. Also includes concentric rings on bottom of plate for easy alignment when installing your router.