Drill bit size: 1 x vice head (8.9 cm). 25 twist drill bits / 0.5mm x 5/0.6mm x 5/1.0mm x 3/1.2mm/1.56mm/1.8mm/2.0mm/2 .35mm/3.0mm (2pcs for each size). The complete drill bit kit pin can respond to your different needs. Precision and durability : the mini hand drill and the 25 twist drills are made of high-grade steel. high speed, which is durable and has a long service life. The non-slip handle makes our manual jewelry drill easy to use. to hold and to turn, to ensure that it is suitable for use. any hobby or precision work. Easy to use. Use: Our manual pin screw drill with 25pcs twist drill bits, just turn the vise head easily, insert 1/2 of the drill bit into the vise head vice, turn it to secure the drill bit, the chuck to the Three precision jaws can keep the drill straight and work well. Many uses: Easy to use. Drill holes in resin, wood, plastic, polymer clay, beads, etc., allows you to create necklaces, earrings, bracelets, pendants, fashion Islands, sculptures, dolls, etc. Essential for all crafts, also used for crafts. as a drill jewelry for stones and twist drill. Note: This is a manual tool, not an electric tool. Twist drill bits cannot be applied to hard materials like steel, iron, stone, glass, etc. The vise should grip approximately 1/2 the length of the twist drill bit when using the hand drill. So the drill bits will not be easily broken.