?NOTICE: Please do read the instruction before installation. If you find the bit can not insert into the drill, READ MANUAL AGAIN! Avoid overheating for continuous polishing in long time which may cause the machine got shock. (Suggest less than 20 Minutes of continuous use each time).100% Satisfy Guaranteed After Sales Service: Contact us If have any Quality Issues, we guarantee 100% refund or replacement. ?Variable Speed Rotary Detail Carver: 0-20,000 rpm Adjustable Speed , controlled by a shaft button, make it easier and safer to polish your nails. Effectively treat both delicate areas and rough callus. ?Portable & Easy to use:High quality metal Pen Shape, handy to operate,Light weight, Low noise, easy to replace bits without any tools;with 50.7" Long USB Cable. ?Widely Used: Professional nail kit machine be used for natural or artificial nails, great for professional use, nail salon, makeup studio or home use. ?Multi Purpose:Uouteo Electric Nail Drill Kit comes with 6 different optional standard metal bits and 6 sanding bands--Each bit has different function, design for Carving, Engraving, Routing, Grinding, Sharpening, Sanding, Polishing.