The Helios RVM 315 is a motor-operated damper intended to prevent cold air from backflowing into horizontal fan systems. It features a cylindrical housing made of sheet steel with flanges on both sides, allowing for direct mounting to the fan base plate. The flange holes are aligned with DIN 24155, page 2 specifications. The damper uses aluminium flaps for effective airflow management, and polymer buffer connections help ensure silent operation. Supplied with a 0.9 m cable, it is recommended to connect the unit electrically in parallel with the fan for proper functionality.