Dorgard has a rubber plunger/stopper that remains in contact with the floor when depressed which allows the door to be held open in any selected position. When the fire alarm is activated the sound is detected within the integral audio electronic pick-up and signals the plunger to retract allowing the fire door to close under normal means.

Dorgard is battery powered so no expensive wiring into the building's fire alarm system is necessary, but operates alongside the existing fire alarm currently in place. Accepted for use by the fire authorities and complies with BS EN 1155 & BS EN 1634-1. The unit has a low battery automatic door release and power-on LED indicator.