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 Smart Power-off Protection :Built-in protection circuit board and intelligent overload protection chip.When the working resistance is too large,it will automatically cut off the power to prevent from damaging the electric engraving pen. Work Rate:10 Watt Rated Voltage:4.2 Volts Rotational Speed:5000 - 18000 r/min For metal, plastic, glass, ceramic, wood, leather, diamond, stone and many more.these bits are enough to work on engraving, carving, sanding, polishing, , routing, grinding, drilling, cutting. Colour:Silver Material:Metal Size:Collet Size:3/32inch Package Contents: 1 x Engraving pen 1 x USB charging cable 1 x Polish bit 2 x Drill bits 3 x Saw bits & 1 connecting stick 30 x Engraving bits 2 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.