【Easy Operation】: The tool features a depth adjustable Special materials stop collar , adjustable to per set depths and produce a counter bored hole on the wood and ensure consistent countersink depth also protect the work surface and anti-clog debris cavities. 【Specialties 】Preventing Scratches Or Marks by Stopper Mounted Bearing，avoids damage to drywall's paper layer and screw recess. Countersink drill bits for wood made to drill, countersink, and counter-bore in 1 step sink counter set. Best adjustable wood countersink drill bits set ideal for woodworking. Hex drill bit set tool made with tapered countersink bits for wood Warm tips: the packaging base is fixed tight, take out the countersink drill bit need to be screwed to the right or shaken left and right, pay attention not to be scratched by the blade.