Efficient Universal Drilling Tools, Multi-Functional Triangular Cross High Hardness Alloy Drill Bit Set, Multi-Material Drill Bit Set,Suitable for Metal Wood Glass (3/4/5/6/8 mm)UNIQUE CROSS ANGLE DESIGN: low cutting resistance, stable drilling, fast speed, and no edge breaking. The opening is neat, smooth, without broken edges, without tremor, and not easily broken. EXQUISITE CRAFTSMANSHIP: Fully polished and anti rust treatment, the drill bit is more wear resistant and durable, automatic polishing, automatic polishing, each one is unique. EASY TO CARRY: light weight, small size, compact design. You can take it with you for