HARDELL Engraving Pen, Rechargeable Mini Engraver Pen with 10 Rotating Grinding Heads, Cordless Portable Electric Micro Engraving Pen for Jewelry, Glass, Wood, Stone, Metal & DIYLARGE CAPACITY BATTERY1200mAh rechargeable battery can provide powerful power without wires, and the battery can be charged through the USB interface. Engraving Pen can generate strong and steady power to complete most DIY craft work. POWERFUL POWERThis electric pen has a 37,000 RPM motor, the motor runs stably at high speed, and it is not easy to heat up for a long time. Pen type push switch, pen press, sensitive contact switch, easy to operate.