Keep your feet warm this winter with our electric heating insole! Made of carbon fiber heating material, it features adjustable temperature in 3 levels and a built-in battery for longer heating time (up to 6-10 hours). Plus, it's cuttable to fit any shoe size! Product name: Electric heating insole Insole material: EVA Insole heel thickness: 2CM Battery capacity: 3300 mAh Ambient temperature: -5-5 Charging voltage: 5V Working temperature: 45-55-65 Charging method: USB charging Usage time: 6-10 hours Button position: three-speed temperature control Input: Type-C 5V/1A Size: can be cut to S (size 35-38) M (size 39-42) L (size 43-46) Power on/off and pairing 1. Press and hold the insole battery button for 3 seconds to enter high gear (red). Double-click the battery button and the indicator light will flash red, green and blue randomly for 1-10 seconds. Then press any gear button on the remote control to pair successfully (Note: pairing is required at the same time) 2. Click the remote control button to start battery life. Press any key on the remote control to change gears Charging instructions: You need to turn off before charging. You need to plug the two charging cable plugs connected to the charger into the interface behind the insole to charge. It will be fully charged in about 3-4 hours (charging is prohibited when the insole is turned on) List: Insoles*1 pair Remote control*1 Charging cable*1 Instruction manual*1