The 12 Volt DC Power Cord (Connects CPAP to Cigarette Lighter Socket) is a 6 foot long cable that connects a DC-compatible CPAP machine to any 12 Volt battery source. One end attaches to the machine’s 12 volt jack and the other plugs into a socket similar to a car’s cigarette lighter outlet. The 12v jack that connects to the machine will fit several of our most popular CPAPs.