1.3 Roller Heads: The callus remover for feet has three different quartz sand roller heads, including a rough roller head for removing stubborn horny dead skin, a medium roller head for removing rough dead skin, and a fine roller for daily foot care. You can choose a roller head of a suitable specification according to your calluses. The rollers spin 360 degrees, at an amazing 40 times a second, and 300 degrees wide angle to gently and effectively buff away hard, jagged skin on the heel 2.2 Speeds Adjustable: The electric callus remover for feet has two speeds, 1700 RPM/min and 2000 RPM/min. The low speed is suitable for daily care or skin with less calluses, while the high speed is suitable for feet with severe calluses or dead skin. You can easily switch between speeds by pressing the touch button 3.Fast Charging and LED Display: This electric foot file callus remover kit is rechargeable and comes with a charging cable. The builtin rechargeable 1200mAh battery can be fully charged in just 3 hours and provides up to 60 minutes of continuous use. The LED display shows the battery level and when to charge, making it easy to keep track of the device's power status. 4.2 Speeds Adjustable: The electric callus remover for feet has two speeds, 1700 RPM/min and 2000 RPM/min. The low speed is suitable for daily care or skin with less calluses, while the high speed is suitable for feet with severe calluses or dead skin. You can easily switch between speeds by pressing the touch button