36 in Backdraft Damper / Wall Shutter, 36-1/2 in x 36-1/2 in, DAYTON, Mfr# 1C209

39 In.H-W 5.75 In.L Alu Wall Vent Shutter, Damper Application Backdraft, For Nominal Duct Diameter Not Applicable, Frame Material Galvanized Steel, Number of Panels 2, Maximum Air Velocity 2500 fpm, Overall Height 39 in, Rough Opening Diameter 36 1/2 in, Rough Opening Shape Square, Fits Fan Diameter 36 in, For Duct Shape Not Applicable, Free Area 7.1 sq ft, Overall Width 39 in, Frame Material Thickness 20 ga, Overall Length 5 3/4 in, Connection Type Not Applicable, Frame Depth 2 1/2 in