Elastic cotton sock with heating system DUAL POWER allows the use of different types of power supply: Direct connection to a 12 volt source (motor battery) – Connection of two Li-PO 12 volt batteries to be inserted in the pocket – Connecting two 7.4V Li-PO batteries to fit into the pocket. The power is 8 Watt at 12 volt & 5 Watt at 7, 4volt.