Woodpeckers TLRSET-ML - 8 Piece Twist Lock Ring Set, Molded. For ideal stock support, it's recommended that the router bit opening be approximately 1/8in. to -1/4in. larger than the bit diameter. This clearance is enough to allow for air flow as well as stock support while routing. These router accessories are in addition to the standard three rings supplied with each Woodpeckers Router Mounting Plate and Router Lift. They come in a handy MDF stand with a total of ten slots. The two additional slots hold the two standard rings that you're not using. Set includes one each, solid, 3/4, 7/8, 1-3/8, 1-5/8, 1-7/8, 2-1/8 and 2-3/8. These new rings are molded from a polycarbonate reinforced ABS. This tough plastic won't chip Woodpeckers' router bits or ding and dent from unexpected drops to the floor. These router accessories are molded to tight tolerances assuring a smooth transition to the surrounding plate material.(Only available as a set.)