Microseven 2.1mm X 5.5mm DC plug extension cable allows flexible option for setting up electronic device such as CCTV camera, printers, LED lamps and signage, sensors, anything that requires DC input and accept 2.1mm x 5.5mm plug, where wall outlet may be out of reach. Comes with female jack at one and a male plug on the other to extend the reach of DC power supply. This unit only accepts 2.1mm x 5.5mm barrel plug from power adapter and will not work with other sizes.