The Helios JVK 60/35 is a heavy-duty volume control damper designed for effective airflow regulation in ducted ventilation systems. Its flanged housing is made of durable galvanized sheet steel and includes connection flanges on both ends for easy installation. The unit features hollow louvre blades mounted on polymer-supported axes arranged in parallel for even adjustment. An external lever provides simple control, and the servo mechanism is positioned outside the airflow to ensure consistent operation, even in dusty or contaminated environments.