MULTI-SIZE: 1pc 15-step drill bit (4-32mm), 1pc 9-step drill bit (4-20mm), 1pc 13-step drill bit (4-12mm). Three sizes are available to meet your needs. The package includes a nylon bag. QUALITY MATERIALS: Classic high speed steel, titanium coating on the surface, proven performance and durability in drilling holes in plastics, wood, aluminum aluminum, copper, stainless steel and many other types of sheet metal. Titanium alloy drill bits are especially suitable for processing copper and aluminum parts / die steel / spring steel / cast iron parts / iron and other metal materials. PRECISE POSITIONING DRILL: When you press the surface, it produces automatic, high-impact, spring-loaded striking force, and an adjustable hood allows you to adjust the striking force. The knurled surface of the brass body is very non-slip, providing precise positioning points without worrying about deviations. EASY DRILLING: The two-blade design provides faster, smoother, smoother drilling. low pressure and high steps so you don't feel stagnation and resistance, with the best speed and precision. LASER ENGRAVED: The size is laser etched into the metal, so that it does not wear out even if it is reused, which facilitates precise drilling.