TruePower 01-0399 Electric Metal Engraver with Carbide Tip and Variable Speed to 7200 Strokes Per Minute Under-thumb power switch for safe & easy one-hand control Easy-to-grip shape for pen-like writing control & comfort Engraves most hard surfaces permanently using high-speed vibration Adjustable engraving force from 0-7200 cycles/min. Carbide engraving tip is quickly removable for easy replacement