- 3/4", 1 3/8", 1 5/8", and 2 1/8" openings (19mm, 35mm, 41mm, 54mm)- Plus one "blank" ring to create a custom ring- Includes molded storage tray with slots- Slots are marked with opening sizeProduct Details This five-piece set of Level-Loc Reducing Rings fits the Kreg Precision Router Table Insert Plate, as well as Pr Kreg PRS3050- Level-Loc Reducing Rings (5-Piece Set)