Electric Nail File Manicure Pedicure Set: This 9v electric nail file set is a mini handheld motor for manicures and pedicures. You can easily use it by plugging the included adapter into a wall outlet. The product features a volume control knob for increasing speed and turning on/off. When changing the bit, make sure the product is not running and is unplugged. Press and hold the button on the tip, turn the tip to loosen it. After opening it enough to allow the bits to fit, insert the tip and tighten it. You can see how the tip is changed in the second photo. It is used for manicures, pedicures, permanent nail polish, and artificial nail applications. Set contents: 6 sanding bits, 6 metal bits, 1 mini drill motor, 1 9v 1a adapter