Powerful, Safe and 2 Speeds AdjustableElectric Foot Callus Remover have 2 speeds:1700x or min when at low speed and 2000x or min when at high speed.If the pressure is too strong,it will automatically stop working and avoid damage to the healthy skin. LED Power Display and Rechargeable Long LastingHigh quality 1200mah large capacity lithium battery has overcharge protection and battery display function,you can see how much battery left and when to charge.The USB charging time for 3 hours,it can powerfully run continuously for about 90 minutes. Note: Please use the charging voltage: 5V or 1A to avoid excessive voltage affecting the service life. IPX7 WaterproofThe electric foot file has waterproof design, whole body can be rinsed under running water. You can use it to make a perfect foot care for your feet when you get out of the shower. It is recommended to dry your feet before use, and then use it for better results.Note: Do not soak it in water for a long time. 3 Replace Grinding HeadCallous removers for feet has 3 different quartz sand grinding heads,rough grinding head can remover stubborn horny dead skin , medium grinding head can remover rough dead skin, fine grinding head use for daily care. You can choose suitable grinding head according to the skin to care,make your feet restore the delicate and smooth skin.