PERFECT SIZE: For precise drilling of various sizes from 5-35mm in diameter, one drill can handle various sized holes. QUALITY MATERIALS: Classic high speed steel, titanium coating on surface, proven performance and durability in drilling holes in plastics, wood, 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. LASER ENGRAVING: The size is laser etched into the metal, so it won't wear out even if reused, making it easy to drill precisely. EASY TO DRILL: The marking hole position and the double flute design make drilling faster and smoother, as well as precise drilling. PRECISE POSITIONING DRILL BIT: When pressing on the surface, it produces automatic, high-impact striking force , spring-loaded, and an adjustable hood allows you to adjust the striking force. The knurled surface of the HSS body is very non-slip, providing precise positioning points without worrying about deviations.