Cordless Electric Mini Drill Grinder Engraving Pen Variable Speed Rotary Tool Features: IMPROVED WIRELESS ELECTRIC GRINDER PEN: This grinding pen comes with rechargeable lithium battery, so you can use it anywhere. Application: Suitable for all kinds of stone carving, wood carving, olive carving, plastic carving, egg carving, glass carving, ceramic carving, drilling and all kinds of metal surface grinding, engraving, trimming, etc. 3 speeds: 5,000 to 25,000 RPM output makes the rotary tool more prominent. Three gear selection can apply to different situations precisely, and make your projects easier and more professional. Dual Usage: Charging and plugging in dual usage, can be connected to the power supply while charging, more efficient. Intelligent Overload Protection: When the resistance is too great, the power will be cut off automatically. Comfortable handy & very lightweight pen format makes your creations more free. Specifications: Power: 25W Voltage: 3.7V Speed: 5000-25000r / min Clamping Diameter: 2.35mm (Suitable for all 2.35MM specification grinding head, reducing drill etc) Size: Approx. Approx.125x16mm / 4.92x0.63 inch Note: It must be fully charged before the first use. Not suitable for large carving, punching, cutting, grinding. slight noise and temperature during machine operation are normal phenomena. Please allow 1-3mm difference due to manual measurement. Due to the light and screen difference, the item's color may be slightly different from the pictures. Thank you for your understanding. Package  Included: 1 x Wireless Electric Grinder 1 x USB Charging Cable