This manual volume damper is designed for precise airflow control in residential and commercial HVAC duct systems. Its stainless steel body and aluminum flap blade provide structural integrity and corrosion resistance, while the integrated silicone edge seal ensures airtight closure to prevent leakage and backdraft. The manually operated handle allows smooth, multi-angle adjustment of air volume without tools, supporting balanced temperature distribution across zones. Installation requires no cutting or fasteners-just slide the unit into the duct and secure it with standard clamps or tape. The 150mm outer diameter and 190mm length suit common round duct configurations, and its compact profile fits tight spaces. The flap operates silently due to low-friction contact between the aluminum blade and sealed housing. It functions reliably in both supply and return air applications, and maintains consistent performance across typical indoor temperature and humidity ranges. No external power or sensors are needed, making it compatible with all standard duct materials including galvanized steel, flexible ducting, and PVC.