This unit has a green LED and a red LED with a built-in common keyed key-switch and an internal sounder. Designed to give an audible and visual indication if a 'Fire Door' is opened, it has an alarm relay output which can be connected to a conventional alarm control panel. This output is shunted and the internal sounder is silenced when the key-operated switch is turned. It also has an additional relay output which operates whilst the unit is shunted, to enable remote monitoring of the unit.
