The Helios RVM 450 is a motorised damper developed to prevent the reverse flow of cold air into horizontal fans. It features a cylindrical housing made from sheet steel, equipped with flanges on both ends for direct attachment to the fan base plate. The flange bore holes comply with DIN 24155, page 2 standards. Fitted with aluminium flaps for dependable airflow regulation, the damper also includes polymer buffer connectors that ensure quiet, vibration-free operation. A 0.9 m electrical cable is included, and the unit should be connected in parallel with the fan to operate effectively.