Product information:

Material: cotton, carbon fiber heating sheet
Is it self-heating: No
Product category: heating socks
Color: gray, black, black soles of feet and insteps of heating, gray soles of insteps and insteps of heating
Specifications: 1 pair of heating socks + 1 pair of 2200 mAh battery, 1 pair of heating socks + 1 pair of 4000 mAh battery
Product voltage: 5V
Battery voltage: 3.7V
Product thermal energy: 35-55°C

Packing list :

1 pair of heating socks, a pair of batteries, usb*1

Product picture: