This is a kind of quality electric grinding machine, compact size, one-hand operation, easy to carry and easy to use. 3-jaw collet design to holds 0.3-3.2mm grinding-head. Multifunction, perfect for engraving cutting polishing drilling use. Works with different grinding heads to fit for more scenarios. Two rechargeable way design, it can be recharged by both 5V powersupply and 3.7V recharge base. You can have a try. Specifications: Name: Electric Grinding Machine Material: stainless steel #43;plastics Battery: 2 * 18650 battery, 3.7V, 1500mAh (included) Clamping-range: 0.3-3.2mm Rotation speed: 18000r/min Output voltage: 3.7V Item size: 27 * 27 * 200mm / 1.06 * 1.06 * 7.87in Item weight: 55g / 1.94ounce Package size: 195 * 100 * 47mm / 7.68 * 3.94 * 1.85in Package weight: 285g / 10.05ounce Packing List: 1 * Electric Grinding Machine 2 * 18650 Battery 1 * 3.7V Rechargeable Base