The Milescraft metal bushing set is comprised of seven carbon steel one-piece bushings, two locknuts and one top hat adaptor. The router bushings have outer diameters of 5/16 in., 3/8 in., 7/16 in., 1/2 in., 5/8 in., 3/4 in. and 51/64 in. This router template guide set comes in a locking storage case with peg hook and a foam insert to keep the accessories in position. Compatible with all router sub-bases with a 1-3/16 in. (30.2mm) center hole diameter and can be used with all Milescraft TurnLock products. These guide bushings are great for use when dovetailing, sign making and inlay routing.