Voltage: 4.2V Speed: 5000-18000r / min<br> Clamping Diameter: 2.35mm (Suitable for all 2.35MM specification grinding head, reducing drill etc)<br> IMPROVED WIRELESS ELECTRIC GRINDER PEN: This grinding pen comes with rechargeable lithium battery, so you can use it anywhere.<br> 3 speeds: 5,000 to 18000 RPM output makes the tool more prominent. Three gear selection can apply to different situations precisely, and make your projects easier and more professional.<br> Dual Usage: Charging and plugging in dual usage, can be connected to the power supply while charging, more efficient.<br> Package Include:<br> 1 * Engraving pen<br> 1 * USB Power wire<br> 2 * Drill bit<br> 3 * Saw blades<br> 30 * Bits<br> 1 * Tungsten steel bit<br> 1 * Connecting stick<br> NOTE<br> 1. It must be fully before the first use.<br> 2. Not suitable for carving, punching, cutting, grinding.<br> 3. Noise and temperature during machine operation are normal phenomena.<br> Colour:As Shown<br> Material:Metal<br> Package Contents:<br> 1 set x engraving machine<br> Only the above package content, other products are not included.<br> Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.