An automatic swing arm, also known as a swing arm operator or swing gate opener, is a device used to automate the opening and closing of swing gates. It is designed to attach to the gate and control its movement, allowing for convenient and automated access.

The swing arm operator consists of a motorized arm or actuator that is mounted on a post or pillar beside the gate. The arm extends and retracts to open and close the gate in a swinging motion. The arm is typically attached to the gate leaf, either directly or via a linkage mechanism, and moves it inwards or outwards to provide an opening or closure.

The operation of an automatic swing arm is controlled by a control panel or a separate controller. The control panel receives signals from various input devices such as remote controls, keypads, or intercom systems, allowing users to initiate the gate's movement. It can also include additional features such as timer settings, adjustable opening and closing speeds, and obstacle detection for enhanced safety.