Dampers prevent air leakage into your fan setupThey are easy to install, fit directly onto the ducting and prevent a back draft of air when the fans are switched offMade of galvanized steel
This Backdraft Damper, 4" is made of galvanized steel, these dampers prevent air leakage into your fan setup. They are easy to install, fit directly onto the ducting and prevent a back draft of air when the fans are switched off.
Brand: Hydrofarm, Model: ACBD4, Size: 4-Inch