USB Cordless Engraver: These engraving tools come with lithium batteries that can be charged via a USB port. When fully charged, it will stay idle for up to 60 minutes when using cordless. Easy to help youperform a better carving process Good Performance: Metal engraving pen with excellent motor, working power 10W. 5000-18000RPM 3-speed adjustment, suitable for different places. With the minimum speed you can safely polish nails,Maximum speed can also be used for metal engraving Portable and Compact: These portable and compact engravers are easy to carry, so you can enjoy a relaxing time of making handmade jewelry. Used for: Can work metal, glass, ceramics, leather, stone or statues. Can also be used for mobile phone motherboard maintenance Easy to use: Our metal engraving tools are easy to use and especially suitable for beginners. Make keychains, DIY necklaces or give gifts with our set Specification: Item Type: Electric Engraving Pen Material: aluminum alloy, electronic components Battery capacity: 300mAh lithium battery Collar depth: approx. 25 mm / 1 inch Applicable Grinding Head Handle Size: Approx. 3 mm / 0.11 inch Power: 10W Charging: 30 minutes to 80%, full charge in 60 minutes Operating time: 3-speed idle operation for more than 1 hour (long-term use can be used during rinsing) Level: Level 3 Speed: 5,000-10,000-18,000 rpm Package list: 1 x polishing pen 1x user manual 1 x charging line 7 x grinding heads