1. Choose the appropriate roller head for your needs: regular coarse for mild calluses, heavy coarse for thick skin, and light coarse for daily maintenance. 2. Apply the roller head to your feet at a 45-degree angle, moving in circular motions. 3. Use the high-speed rotation (2200-2500 RPM) with adjustable speeds for quick results. 4. The device has a runtime of up to 3 hours and can be recharged via the dual-pin port in 3.5 hours. 5. The built-in LED spotlight and digital display help monitor battery life and speed settings. 6. After use, rinse the device under water and store it with the protective cap on. 7. Avoid applying too much pressure to prevent injury. 8. The device will automatically turn off after 20 minutes of inactivity.