" Easy one-handed operation without the need for a hammer. Mark a recessed starting point on a metal (steel, aluminum, brass, copper), wood, glass, leather or plastic surface to prevent the drill or the screw from slipping. 5" overall size for excellent durability. Consists of a chrome tip and a premium stainless steel body with a non-slip knurled texture that allows you to work with great comfort and precision. With a tension screw, you can set the optimum tension for the job by simply turning the knob. This will allow you to control the impact pressure of the double spring barrel and give you the correct indentation on any material you use. Supplied with 2 spare nibs, hardness 58. It's not just a center punch, it's a safety tool in the car. The product's ability to work on glass means it can easily shatter car windows to help you escape in an emergency. Of Plus, 5 inches is very space-saving in a car. "