Special Design - Steel countersinks or pilot hole. Drill and countersink in one step, will not bend, and drilling can be done quickly and accurately. Fast Positioning and Chip Removal - 5-tooth countersink, faster sawdust removal, three-point positioning, not easy to slip, quasi-drilling and fast. Detachable and Adjustable - Adjustable depth of sleeve with a hex key, the drilling length can be adjusted with a key to remove or adjust the adjustment screw. Durable High Carbon Steel - Heat-treated and tempered carbon steel with titanium coating for superior cutting power. Application - Suitable for use on wood, PVC and plastic panels. Not suitable for glass, iron plates and steel plates.