Adjustable Speed: This electric engraving pen has 3 adjustable speeds (5000 rpm, 10000 rpm, 18000 rpm), suitable for different occasions. Generally, low speed for metal/wood, high speed for glass/ceramic. Rechargeable and Smart Shutdown: The engraving pen is rechargeable via the USB interface. Cordless use lasts up to 60 minutes after a full charge. The micro-metal engraving pen has a built-in safety protection circuit and an intelligent overload protection chip. If the pen is too large, the power will be automatically cut off to prevent damage. Truly safe to use. Visible Indicator: Equipped with a speed indicator, an electric quantity indicator, and an overload indicator, you can see the usage status of the engraving pen in real time without power. You can adjust the desired working speed for different applications. Wide Use: This mini engraving pen is small and elegant, weighing only 40g. Its metal surface and design provide a comfortable feel. It can easily polish and engrave jade,