Safety Design: Designed with automatic overload protection to prevent overheating. In case of overheating, automatic overload protection will be activated. MULTI-FUNCTIONAL: Our electric nail file with 6 bits is suitable for natural or artificial nails, for sanding, cutting, carving, polishing all kinds of nail art. EASY TO USE: Plug the USB cable into the USB adapter (or any USB port source) and into the mains power outlet. Select the desired speed by turning the variable speed control knob on the phone. Easy to carry: This mini electric manicure device is so pretty and lightweight, you can take it anywhere, just put it in your handbag, luggage, etc. It is a professional electric manicure/pedicure polishing tool for nail salons. Adjustable Speed: Adjustable speed and rotation, the speed of this nail drilling machine can be adjusted from 2000 to 15000 rpm. Low noise, low vibration and adjustable high speed for professional manicure.