The Helios RVM 250 motorised damper is designed to block cold air from entering horizontal fans. It operates via an integrated motor and features a cylindrical housing made from sheet steel, with flanges on both sides for easy installation. The unit can be directly mounted onto the fan’s base plate, with flange holes matching the DIN 24155, page 2 standard. Fitted with aluminium flaps, it ensures effective airflow control, while polymer buffer connectors help maintain quiet operation. The damper comes with a 0.9 m connection cable and is best connected electrically in parallel with the fan.