Hello dear customer.thank you for your purchase.If you encounter product problems or operational problems and other problems, you can contact our customer service immediately, and we will solve the problem for you within 24 hours.Please be sure to contact our customer service.I wish you a happy life! ! ! Pin Vise Hand Drill: Material: alloy Color: black Size: 3.74 inches/ 9.5 cm long How to use pin vise: Step 1: take out the suitable drill bit, and half unscrew the vise head. Step 2: half insert the drill bit, and screw the head tightly. Step 3: target the place where you are going to drill a hole, use one hand to fix the top of handle while using the other hand to rotate the handle. 48 Piece Twist drill bit: Material: steel Color: Silver Size: 3 Pieces of 0.5，0.6，0.7，0.8，0.9，1.0mm size, total 18 piece; 2 pieces of 1.1，1.2，1.3，1.4，1.5，1.6，1.7，1.8，1.9，2.0mm size, a total of 20 pieces; 1 piece of 2.1，2.2，2.3，2.4，2.5，2.6，2.7，2.8，2.9，3.0mm size, a total of 10 pieces 10 Pieces PCB Mini Drill Bits: Material: Tungsten steel Color: color send random Size: 0.3-1.2mm Color: color send random The shank diameter is approx. 3.175 mm, overall length is approx. 38 mm, which fit for processing PCB, normal FR-4, CEM-3 boards, SMT, CNC, molds, plastic, circuit board, carbon fiber, composite board and so on Package include: 1 x Pin vise 48 x Twist Drill bits 10 x PCB Mini Drill Bits Warm Tips: Not suitable for hard materials like iron, steel, stone, glass, tile, etc.. The pin vise is manual, not electronic. Small hand drill, only can clamp the drill bits of under 3 mm. Manual measurement, please allow slight difference.