Heated insoles keep your feet warm even in the coldest weather. Perfect for hiking or everyday use. When connected to a power source via a USB connector, they heat up to a temperature of 40 - 50 °C. The universal size can be adjusted by trimming along the pre-marked line. For best results, we recommend pairing the insoles with the CXS power bank (6121 039 000 00). When fully charged, this power bank provides approximately 5 hours of heating.