Optimize your HVAC system with this manual air damper, designed for precise control. Its smooth interior surface promotes efficient airflow, while its anti-backflow feature ensures no unwanted air or enters your . Available in multiple sizes, this damper is ideal for any ducting requirement. Features -Color:White -Material:PVC -Size:16.00X11.80X11.80cm/6.29X4.64X4.64in -Size:16.00X11.00X11.00cm/6.29X4.32X4.32in -Adjustable airflow control: the manual ducting valve provides adjustable airflow control, allowing users to finetune ventilation to suit different environmental needs -Efficient air movement: featuring a smooth and flat interior, the damper ensures efficient air movement, reducing resistance and enhancing overall system efficiency -Backflow prevention: designed to prevent backflow, this damper is ideal for use in central ventilation systems and range hoods, effectively stopping reverse airflow and leakage -Easy to install: the damper's design makes it easy to install, allowing for quick and convenient integration into various duct systems without requiring tools -Multipurpose: the hvac control can accommodate different duct dimensions, providing flexibility for various installation requirements Package list: 1 volume regulating valve