Features:1. Safe and environmentally friendly materials, the latest high-efficiency carbon fiber heater; High density, must be used with power banks.2. Temperature time varies in different environments. The temperature will be as high as 50 deg;, which will warm your feet without sweating in winter.3. The heated insole is made of soft elastic EVA foam, which has good softness and elasticity. When the insole fits your shoes, your feet won't feel firm.4. Cut to the right size - you can adjust it to your shoe size and cut the sole to meet your needs, from 35-40 Euro and 41-46 Euro.5. Keep your feet warm. The insole heated by the power bank can solve the discomfort of the foot in cold weather. Keep yourself alive in certain winter activities (such as hunting, skiing, motorcycles, climbing or walking, etc.), simple and easy-to-use operations. Specification:Name: heating insoleMaterial: composite fiber/carbon fiberTemperature control: 40 deg; C-50 deg; C (depending on the environment) Size: 35-45 yards (can be cut) Input Voltage: 5V 2A Packing List: 1 Pair * Heating Pad1 * USB Cable