DAYTON 2C521 Wall Backdraft Damper, Vertical, Wall, 18 1/2 in x 18 1/2 in
$56.79
21 In.H-W 6 In.L Aluminum Wall Backdraft Dampr, Damper Application Backdraft, For Nominal Duct Diameter Not Applicable, Frame Material Galvanized Steel, Number of Panels 1, Maximum Air Velocity 2000 fpm, Overall Height 21 in, Rough Opening Diameter 18...