Smart Rechargeable Grinding Pen Portable Grinding Head Rust Removal Polishing Motherboard Repair Electric Grinder 1. Charging input: DC 5V 0.5A 2. Battery voltage: 3.7V 3. Motor speed: 12000rmin 4. Power: 3W 5. Material: Aluminum 6. Battery capacity: 650mAh 7. Packing list: host x 1, grinding head x 8, Type-C charging cable x 1, manual x 1 8. Size: about 15.5 x 1.6cm 9. Weight: about 52.8g Features: 1. Suitable for repairing chip IC grinding, cutting motherboards, brackets, removing screws and other applications 2. Precision chuck, firmly fixed, no skew or shaking, rotating shaft tightly connected, high concentricity 3. Enhanced power motor, long-lasting and durable operation, strong power output, sufficient power to meet various work needs 4. Built-in lithium battery, Type-C charging interface, stable and safe output 5. With a variety of large grinding heads, choose different accessories to meet various needs, easy to replace 6. 3 adjustable gears, sensitive touch switch 7. Lightweight and portable, comfortable to hold, one hand can complete various operations