The Helios RVM 355 motorised damper is designed to prevent cold air from flowing back into horizontal fans. It features a cylindrical housing made of durable sheet steel with mounting flanges on both sides, allowing it to be directly attached to the fan base plate. The flange bore holes conform to DIN 24155, page 2 standards. Equipped with aluminium flaps for efficient airflow control, the damper also incorporates polymer buffer connectors for quiet operation. It comes with a 0.9 m connection cable and is intended to be electrically connected in parallel with the fan to ensure coordinated operation.