Control the size of the bit opening on your router table with JessEm's 10-piece insert ring set. These rings feature JessEm's unique Tab-Lock design that enables you to lock and release them with a simple 1/4-in. turn of the insert wrench (not included). Each ring is clearly labeled with its opening size, and the set comes with a convenient storage caddy that holds a total of 14 rings. This set includes rings with the following diameter openings: blank (to customize for your personal needs), 1/4 in., 3/8 in., 1/2 in., 3/4 in., 1 in., 1-1/4 in.,1-1/2 in., 1-3/4 in., and 2-1/4 in. NOTE: The size range of this ring set complements the sizes of the 3 rings JessEm includes with their router lifts -- no duplicates!