Precautions: Keep the nail surface dry and clean before polishing, choose the appropriate drill bit, and adjust the machine to the appropriate direction and speed How to use: 1. Insert the nail drill bit 2. Insert the adapter 3. Plug the USB cable into the mobile power supply 4. Select the rotation direction and speed 5. Start polishing nails Packing list: nail drill*1, pen cap*1, Type-c charging cable*1, connecting cable*1, metal polishing head*6, manual*1 Packaging size: 7.1 x 8.7 x 2.4 inches; Packaging weight: 1.39 poundsExquisite appearance: ABS+aluminum alloy body, easy to hold, light weight, non-slip, scratch-resistant, elegant appearance, and also a good gift choice. Convenience: It can work for about 5 hours after being fully charged, and it can be fully charged in 2 hours. Suitable for natural nails and artificial nails, allowing you to easily care for your nails. Powerful function: 0-45000 RPM, and there is an R/F button to control the forward and reverse rotation direction. The acrylic nail file with a smart LCD screen displays RPM, direction, and battery power, providing uninterrupted convenience. Powerful core: With a powerful silent motor and intelligent heat dissipation function, the machine maintains low heat, low noise, and low vibration when in use, and you can use it anywhere without disturbing anyone. Professional nail drill: The kit contains nail drill*1, pen cap*1, Type-c charging cable*1, connecting cable*1, metal grinding heads*6, and a guide, so even beginners can easily master the use method.