Starrett A6-4 Kwik-Change Arbor Kit with High Speed Steel Drill. Offers fast, tool-free changes between different sizes and types of holesaws,. It also provides a simple method for core ejection and hole enlargement.
Specifications:
Holesaw Diameters: 14-152mm.
Chuck Size: 9.75mm (3/8in).
Hex Shank Size: 8.75mm (11/32in).
Screw Thread: 1/2in-20 UNF, 5/8in-18.