The Helios RVM 280 is a motorised damper specifically designed to prevent the backflow of cold air into horizontal fan systems. It features a cylindrical housing made of sheet steel with flanges on both ends, allowing it to be securely mounted directly to the fan base plate. The pre-drilled flange holes comply with DIN 24155, page 2 standards. The damper uses lightweight aluminium flaps for efficient airflow control, and polymer buffer connectors ensure quiet operation. It includes a 0.9 m connection cable and should be wired in parallel with the fan for synchronized performance.