Features: -Built-in 300mAh rechargeable battery, wireless use can last up to 30 minutes after fully charged. With a battery indicator and an overload indicator, you can know the application status of the engraving pen in real time.-There are 3 levels of adjustable speed (5000, 10000, 18000 rpm), you can adjust according to different applications. Usually, metal and wood need low speed, glass and ceramic need fast speed.-Adopting intelligent overload protection chip, the power will be automatically cut off when the resistance is large (press too hard), ensuring safe use.-The lightweight and compact design provides comfortable use, you can hold it like a pen, allowing you to complete complex work smoothly and easily.-Suitable for any material, such as met.