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 will 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 will not feel very noisy. Great for beginners and professionals to use anytime, anywhere to make unique creations that you like This is the latest and newest set of engraving pen, all these bits are enough to work on engraving, carving, sanding, polishing, , routing, grinding, drilling, cutting. Power source: USB charging Work Rate:25W Transfer Speed:5000-18000r/min Rated voltage:3.7V Diameter of bits:2.35mm Around 3-5 hours idling after full charge Tungsten Steel Bit: The hardness of tungsten steel bit is 91HRA ,which often work on hard metal and glass,specially, it can help your glass work. Power-off Protection: When tool encounter great resistance, it will shut off automatically to protect itself to extend using life.Then you just need to press ON/OFF button to start working again. USB Power Charging The electric jewelry drill powered by USB interface, it can meet your outdoor using after finishing charging.It can also be used while charging, but we suggest you to use after charging to extent battery using life. Colour:Black Material:Metal Package Contents: 1 x Engraving pen 1 x USB charging cable 1 x Polish bit 2 x Drill bits 3 x Saw bits 30 x Engraving bits 16 x Stencils Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.