Easy one-hand operation without hammer. Mark a dimpled starting point in metal (steel, aluminum, brass, copper), wood, glass, leather or plastic surface, prevent drill bits or screws from slips away. With excellent durability. Compose with chrome plated tip and high quality stainless steel body, with anti-slip knurled texture offering you very comfortable and precise operation. With the tension screw, you can adjust the best tension apply on your work by simply spin the knob. This will allow you to control the striking pressure of the double spring loaded barrel and give you the correct indentation on the materials you are using. More than a center punch, its also a safety tool in car. This product is able to work on glass that means it can break the car window easily to help you escape out if any emergency situation happened. Besides, 5 in dimension is very space saving in cars. Spec Color: Black & Silver Spring material: stainless steel, shell material: high carbon steel Size: 12.8 cm long Package includes: 2 pcs*center punch 2 pcs*replacement tip