Product Description:* 1. Uniform heating, high temperature transfer efficiency, fast heating speed, soft and convenient.*2. Easy to use. Just put on your shoes and turn on the power to enjoy the warmth.* 3. Soft and comfortable, good workmanship, ultra-thin design, maximum flexibility, only 4mm thick.*4. Use waterproof material that can be cleaned directly. More comfortable, cleaner, according to the line for any trimming, the insoles can be cut according to the shoes* 5. 100% brand new and high quality. Product Specifications:Product Name: USB InsertsMaterial: EVA Flexible FiberHeating Material: Far Infrared Carbon FiberTemperature: About 40 - 50° Voltage: 5V/2A Optional Dimensions: 35-39, 40-46 (For Any Trimming)Packing List:Inserts*2USB Line*1Note:1. All photos have been specially colored, but due to different lighting conditions and different display settings, there may be some deviations in the photos and objects you see. Please understand2. The data is measured manually and there may be some variance, but this does not affect usage.