The Helios RVS 315 is a motor-operated damper built to prevent cold air from flowing back into horizontal fans. It features a cylindrical sheet steel housing with flanges on both ends, allowing for direct mounting to the fan base plate. The bore holes are positioned according to DIN 24155, page 2 standards. Quiet operation is achieved through the use of a polymer buffer connection, making the unit suitable for applications requiring silent and efficient airflow control.