The Helios RVM 630 motorised damper is designed to prevent the backflow of cold air into horizontal fan systems. It features a cylindrical housing made from sheet steel with flanges on both ends, enabling direct attachment to the fan base plate. The flange bore holes comply with DIN 24155, page 2 specifications. The damper is fitted with aluminium flaps for efficient air regulation, while polymer buffer connections ensure smooth and silent operation. A 0.9 m connection cable is included, and for optimal performance, the unit should be electrically connected in parallel with the fan.