Feature: 1. EXQUISITE CRAFTSMANSHIP: The heating material of the insole is made of far infrared carbon fiber, which is made into a soft sheet heating material with a thickness of only 0.2mm, which generating uniform heat. 2. SAFE AND RELIABLE: The output voltage of the USB interface is only 5V, the output voltage of the adapter is only 6V, and with voltage stabilization protection device, the two output voltages are lower than the human body safety voltage of 36V, safe and reliable. 3. ENERGY SAVING: Due to equipped with carbon fiber heating material, its power is less than 8W, an average of 125 hours to consume 1 degree of electricity, which is very energy saving. 4. PRACTICAL INSOLES: Our heated insoles can be placed inside existing shoes, they are flexible and easy to use for a wide range of people. 5. APPLICABLE SCENARIOS: Our insoles will provide you with enough warmth in the cold winter months, and you can use them while hiking, skiing, camping, and fishing. Specification: Item Type: Electric Heated Insoles Material: EVA polyester Heat Material: Far infrared carbon fiber. Package List: 2 x Shoe Insole1 x USB Cable1 x Instruction Manual Note: This product does not contain batteries, there is no renewal of the warmth function, you need to connect the power to heat, power off will immediately cool.