A total of 57 pieces: including a 1 pin vise electric drill + 46 micro twist drills + 10 mini PCB electric drills for you to DIY handmade. PCB micro drill: The PCB micro drill is made of tungsten carbide, suitable for processing PCB, ordinary FR 4. CEM-3 board, SMT, CNC, mold, plastic, printed circuit board, carbon fiber, composite board, etc. Micro twist drill: The micro drill is lightweight and compact in size. It does not take up extra space. It is used to process wood, plastic, rubber, PVC, walnut, model, bone, angle steel, amber, olive, fiberglass and other materials. Hand drill pin vise: aluminum alloy, strong and durable, its tail can be rotated, strong and easy to use