How to Use: 1. Connect the power cord of the sanding pen to the socket marked "Motor" (DC motor connector) on the right side of the control unit. 2. Long press the left button to turn on/off. 3. The speed control knob can start/stop the motor and adjust the speed. 4. Press the speed control key to pause the speed, and press it again to resume the speed. 5. Press the forward/back button to select the F/R direction 6. The motor speed can be changed between 0‑40,000 rpm and displayed on two LCD displays. 7. The large LCD screen can display speed, battery power and F/R direction. Specification: Condition:100% Brand New Item Type: Nail Drill Machine Material: ABS, Metal Power: 80W Voltage: 100~240V Speed: 40000RPM Battery Type: Built-in Battery (Battery Included) Battery Capacity: 2600mah Charging Time: 2.5 Hours Life Time: 7.5 Hours Features: The brushless grinder has low temperature rise, low energy consumption, long life, speed up to 40,000 rpm, silent and no jitter, automatic control of the start and stop of the motor, automatic protection device, and no blocking under high-speed operation. Usage: Household, nail salon, etc. Package List: 1 x Main Unit1 x Sanding Pen 6 x Sanding Head 6 x Sanding Ring 1 x Pen Holder 1 x Instruction 1 x Adapter