Intelligent Power-Off Protection: Rechargeable USB type-C charging metal engraver pen, there is a built-in overload protection chip, when the resistance is too high, it automatically power off to protect it, and prolong the service life of the jewelry engraving machine 3 LEVAL VISIBLE SPEED ADJUST: This electric engraving pen for all material is about 5000-18000r/min, and different speeds are used to engrave different materials. The engraving pen is and ergonomically designed to give you precise control and engraving. Low Noise: The sound of this cordless rotary tool is very low when working, even if someone is sleeping, he or she not feel very noisy. Great for beginners and professionals to use anytime, anywhere to make unique creations that you like. all these bits are enough to work on engraving, carving, sanding, polishing, , routing, grinding, drilling, cutting. Material: plastic+metal colour: Package Contents: 1 x host 1 row grinding needles 3 x saw bits 1 x connecting stick 2 x drill bits 1 x polish bit 3 x stencils 1 x USB charging cable