12" Backdraft Damper
12" Backdraft Damper at HorticultureSource.com -
12" Backdraft Damper (403012) Made of galvanized steel. Prevents reverse air flow when fans are shut off. Saves CO2 and prevents odors from flowing backwards. Rubber gasket pre-installed on exterior for an air tight seal. Manufacturer's Product Information MSRP $ 49.95 Dimensions 12 x 5 x 12