Its a DC barrel Jack male connector that fits with standard 2.1 x 5.5 mm DC barrel jack female connector.
The outer shell unscrews to reveal solder terminals and a crimp strain relief. This general-purpose connector can be used in a variety of applications where a male 2.1mm DC barrel jack is there to receive DC power. DC Jack, also known as a power jack, DC power jack, male jack, male plug, etc, is used to give external DC power to any device or board. It has a cylindrical miniature size. It is a perfect option to give direct external power to the board or any devices.