About This Item Premium Quality: Made of high speed steel with titanium coating, fully polished, forged and heat treated, strong and durable. Titanium coating to reduce friction and heat from steel. Comes with a 4-12mm five-step bit, a 4-20mm nine-step bit, and a 4-32mm fifteen-step bit. Hex shank: Comes with one shank standard 6.35mm hex, fits all power tools such as electric drill and electric screwdriver. Hex shank can just stick drill bits stably in bit holder without screwdriver, prevent slipping when chuck. Dual flute design: Double flute design for optimal speed and precision, smoother cutting, each step is clearly labeled with the diameter of the depth in steps. Comes with a little pressure and very easily cuts through wood, brass, steel, plasterboard and other surfaces. Exquisite workmanship: marks hole locations and starts drilling holes drill bits and screws, preventing slipping - Heat treated alloy steel punch with sharp precision tip - Corrosion resistant brass body with non-slip knurled handle. Includes a handy nylon storage pouch to protect them. Multi-purpose: suitable for cutting holes in a variety of materials including mild steel, brass, wood, plastic, aluminum, copper, plasterboard, metallic materials, fiberglass, PVC, etc. Easy to carry with nylon pouch, convenient to store in bag, car or home. Perfect for professional and home use.