This product is suitable for keeping warm in winter, preventin cold and preventin frostbite.There are yardage cutting lines on the sole surface, which can be cut to the desired size according to the needs. The arch effect is more fit and comfortable.Designed with a temperature remote control device, different buttons on the remote control are used to control different operation modes, and the temperature can be controlled according to your own needs.Built-in lithium battery, can be used when fully charged, no need to tie the battery, no need to connect to the power supply.It can release far-infrared rays when heated,prevent frostbite of the feet, reduce fatigue, etc.Specifications:Product name: electric heating insoleMaterial: EVAVoltage: 3.7VBattery capacity: 2100 mACharging voltage: 3V-5VPower output efficiency: 98%Overcharge protection voltage: 5VOverload protection voltage: 2.85VCharging method: USB chargingSize: Large: 41-45 yards (can be cut)Temperature: The high temperature range can reach 60-65℃, the use time is about 3-4 hours, the middle range can reach 50-55℃, the use time is about 4-5 hours, and the low range can reach 40-45℃, and the use time is about 6-7 hours.Insole use and operation:1. Long press the switch for 3 seconds, the LED indicator lights up, and the red light turns on, indicating high temperature.2. Click again, the blue LED light is on, indicating medium temperature.3. Click again, the green LED light is on, indicating low temperature.4. Press the off button on the remote control to turn off.Remote control operation:1. Press the remote control H/ON to turn on the high temperature2. Press the remote control M to turn on the medium temperature3. Press the remote control L to turn on the low temperature4. Press the off button on the remote control to turn offPackage included:heating ins