25 In.H-W 6 In.L Aluminum Backdraft Damper, Damper Application Backdraft, For Nominal Duct Diameter Not Applicable, Frame Material Galvanized Steel, Number of Panels 1, Maximum Air Velocity 2000 fpm, Overall Height 25 in, Rough Opening Diameter 22 1/2 in, Rough Opening Shape Square, Fits Fan Diameter 20 in, For Duct Shape Not Applicable, Free Area 2.5 sq ft, Overall Width 25 in, Frame Material Thickness 20 ga, Overall Length 6 in, Connection Type Not Applicable, Frame Depth 2 1/4 in Featuring louvers felted on leading edge for quiet operation, this DAYTON backdraft damper/wall shutter has shutters that open automatically when fan is activated. Model has 26-ga. mill-finish aluminum louvers, nylon bushings, and stainless steel pivot pins. Mounting holes: 9/32" x 1/2". Unit is not for use wit.
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