The Respironics EverGo DC Adapter plugs into any 15-20 amp circuit, such as in a car or boat. The Respironics EverGo DC Car Charger is 6 feet long and connects a DC-compatible EverGo portable oxygen concentrator to any 12 Volt battery sources, such as car's accessory outlet. The EverGo DC Power Cord features a fully molded design for maximum durability and long life. Keep as a spare cord for convenience or replace your overused or misplaced power cable, or just get some extra cords for convenience. Note: For EVERGO UNITS with a Serial Number 109501 and greater.