[Adjustable speed]: this professional nail drill machine is equipped with high-quality bearing, which enables it work smoothly at a high and adjustable speed (00-35rpm) by rotating the speed control knob easily [LCD display screen]: large led display shows the working speed, rotation direction, and remaining power clearly there are forward and reverse rotation directions, suitable for left and right hands [Rechargeable battery]: designed with a high-quality aluminum alloy comfortable hand piece, the nail drill machine with a built-in 2600 mah lithium battery can last 4 hours but just need 1 hours to charge [Great design]: portable and convenient, its size is small, you can take it easily and this nail drill machine comes with a clip on the back which could hang on your clothes, or put it in your pocket or bag [Multi uses & professional nail drill kit]: the electric nail file comes with 6 different metal drill bits and 6 pcs sand bands for buffering, grinding, sharpening, extension gels removing, and calluses smoothing