This adapter allows you to connect a barrel jack connector to bare wires. One end has screw terminals and the other has a 5.5x2.1mm center-positive male barrel jack. If you need to connect bare wires to a barrel jack on an Arduino or a development board this might be the simple solution.

With this Power Jack you can feed various power source to your Arduino project from 9V battery to 6xAA battery. A sample use is illustrated below. The 9V battery clip is also available at

This picture is just for illustrated purpose.