XCSOURCE 22PC Countersink Drill Bit Set W/Adjustable Depth Stop Collars Counterbore Drill Woodworkers Hole Cutter Screw Drill BI034 Special designed steel counter sleeve countersinks or counter bores pilot hole. Adjustable counter sleeve depth with wrench. Drill and countersink for wood screws without changing bits. Drilling length can be adjusted for various length screws simply by loosening and tightening the setscrew. Suitable for drilling machines with chucks or adapters and drilling in hard wood and wood layer, machine screw wood screw.