Solid, Flat and Perfectly Level Mounting Surface: This rugged 3/8 in. thick (9.5 mm) phenolic insert plate is designed to provide a solid, flat and perfectly level mounting surface for your router. Measuring 9-1/4 in. x 11-3/4 in. (235 mm x 298 mm), it will accept almost any router (even large, heavy models) with ease. No Unecessary Mounting Holes: Mounting your router to this plate is easy, but it isn't cluttered up with a bunch of extra predrilled mounting holes that you won't need. Instead, this plate has alignment marks on the underside that make it easy to center your router, plus a series of starting points that make it easy to drill the mounting holes for many popular routers. Just follow the detailed instructions that are included with the plate to have your router mounted accurately in no time. Level-Loc Reducing Rings: The plate is equipped with our Level-Loc Reducing Rings that allow you to easily change the size of the opening around the router bit. These rings simply twist into place using an included ring wrench to lock in level and flush with the plate surface. The plate comes with 3 Level-Loc Rings: 1 in. (25 mm), 1-3/16 in. (30 mm) for use with universal-style guide bushings and 2-5/8 in. (67 mm). Undrilled and Predrilled Plates: The Precision Router Table Insert Plate is available in 3 versions, so you can choose the 1 that best suits your needs. Material: Metal.