Strong, Transparent & True: Made from durable PC plastic that resists impact, offers clear visibility of the bit and cutline, and maintains consistent thickness and flatness for stable routing Wide Compatibility: Fits many mainstream routers including 1617, 1618, 616, 618, 690, RT1322, RT1323 and more Guide Bushing Ready: Accommodates standard Porter-Cable style router guide bushings Complete Hardware Included: Includes 5 sets of mounting screws for various router models and a brass centering cone (1/4" shank) for easy initial alignment Auto-Centering Design: The center hole features a self-centering shoulder that keeps the bushing aligned with the bit every time — no need to re-center when changing bushings (Patent Pending) This convenient woodworking tool adds precision to your routing applications as you work freehand with a handheld router, while you can find the model of your router and the corresponding letter that accommodates a wide assortment of standard routers. This universal router base plate Ideal for edge routing with bits that are on both straight and curved edges. Maintenance: Carnauba wax applied to the base plate will reduce the opportunity of scratching. If scratching occurs, careful use of a plastic polish will remove them. Works with 1/4" router collets For use with 5/16" to 5/8" inner diameter template guide bushing