Kilargo circular intumescent fire dampers maintain the fire-resistance performance of walls and floors where round ventilation ducts pass through a fire-rated element. The low-loss damper is factory installed in a circular sleeve, has no moving parts and allows bi-directional airflow during normal operation. When exposed to fire, the intumescent core expands to close the opening. The range supports quick installation across approved wall, floor and retrofit systems and is tested in accordance with AS 1530.4.