Fuller Quick Change Countersink Set #9 Very similar to the Deluxe set #8 but has the Quick-Change Hex shank system and also does not have plug cutters. Contains five type- C countersinks mounted on Hex Shank taper point drills with Quick Change Chuck Adapter. Countersinks are for wood screw sizes #6, 8, 10, 12, and 14 with 3/8" and 1/2" cutting diameters. Also included are 3/8" and 1/2" Stop Collars, two hex keys to fit countersink screws, and an attractive mahogany case. Once you start using the Quick-Change system it's hard to go back to traditional bits. They are a real time-saver.