Premium Holesaw Arbor is the best option for all DART holesaws, it will also fit most other holesaws available. The arbor has a unique thread that allows two holesaws to be mounted inside each other, making it easier to enlarge holes. It comes with our standard 83mm pilot drill, which can be interchanged with any of our other holesaw pilot drills. This arbor has a 11mm Hex shank, and can be used on holesaws from 32 to 210mm.