The Helios JVK 30/15 is a volume control damper featuring a frame housing with double-sided connection flanges, crafted from durable galvanized sheet steel. It is designed for duct fan integration, with hollow slats whose axles are mounted in plastic for smooth operation. All slats adjust simultaneously in the same direction via an external lever. The adjustment mechanism is positioned outside the airflow, protecting it from contamination and ensuring trouble-free performance.