Fuller # C5M.
. # 10 Complete Countersink W/Taper Drill & Quick-Change 1/4" Hex Shank Adapter From W.L. Universal 1/4-inch quick-change hex shank prevents slipping in standard chucks and is compatible with all 1/4-inch quick-change chucks, including impact drills; Suitable for drilling holes on board of low hardness such as wood, plastic and other soft material.