How to Use: 1. Connect to the host of grinder 2. Grinding head can be installed and removed by rotating handle button Specification: Item Type: Electric Nail Drill Pen Handle Material: Aluminum Alloy Speed: 35000rpm Size: Approx. 14.5 x 2.5cm/5.7 x 1.0in (Manual measurement, there will be a little error) Characteristics: 1. High-quality material, pen design, comfortable grip, easy to use, sturdy and 2. Two optional adjustable directions of forward and reverse 3. Slight vibration, extremely quiet and stable operation 4. Drill bit can be easily replaced without tools 5. High speed 35000 rpm Package List: 1 x Electric Nail Drill Pen Handle