Flap Exhaust Valves (Flap Stacks) Trapeze Hanger and Angle Ring connections

and Angle Ring connections

Diameters are +/-  1/8 inch

If you require 20 feet

They are recommended for high moisture systems

Very heavy duty to withstand years of use

Flap Exhaust Valves (Flap Stacks) Trapeze Hanger and Angle Ring connectionsA resourceful after the fan product, flap exhaust valves, or stacks, are designed to open, like bird wings, with the airflow and close when the system is not exhausting. The lightweight and balanced blades produce minimal resistance to exhaust. The design of the housing and blades channel rainwater away from the opening and allow it to drain without intrusion into the ducting. Available in 4" to 32" diameter (contact for custom sizes). Also known as