The Inogen One DC Power Cord plugs directly into the G3 or G4 unit and connects into most standard DC outlets that are found in most cars, trucks, boats or RVs. The Inogen G3 will normally operate and recharge the battery when it is plugged into the DC power source. The 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. This power cord is designed for use with the Inogen One G3 and Inogen One G4.