MaterialMark a starting point with pins in metal (steel, aluminum, brass, copper), wood, glass, leather, or plastic and prevent drills or screws from slipping. AdjustableThe automatic center punch has a built-in spring to adjust the tension; you can adjust the cover clockwise or counterclockwise for optimal performance. Wide ApplicationThis automatic center punch can be used as a manual punch tool on wood, soft metal, and glass. It may also be used to break car windows in emergency situations. Easy to UseSimple one-handed operation without the need for a hammer. Ideal for users who require single-handed functionality. This self-punching tool is a valuable addition to any household toolkit. SpecificationThe metal punch is 128mm (5.04 inches) long and 11mm (0.43 inches) in diameter. The set includes two automatic center punches and two replacement tips. The compact design is portable and easy to carry.