The Airmiq 150mm metal backdraft damper maintains one-way airflow in round ventilation ductwork. Internal blades open automatically when the fan is operating and close when airflow stops, helping prevent wind, pressure differences and neighbouring systems from driving air back through the duct. Manufactured for connection to 150mm round metal duct, the damper provides a durable solution for bathroom, kitchen and general exhaust applications. It should be installed in the correct airflow direction and positioned where the blades can operate freely and remain accessible for inspection.