36 in Backdraft Damper / Wall Shutter, 39-1/2 in x 39-1/2 in, DAYTON, Mfr# 53DR18

42 In.H-W 5.75 In.L Aluminum Wall Fan Shutter, Damper Application Backdraft, For Nominal Duct Diameter Not Applicable, Frame Material Aluminum, Number of Panels 1, Maximum Air Velocity 2500 fpm, Overall Height 42 in, Rough Opening Diameter 39 1/2 in, Rough Opening Shape Square, Fits Fan Diameter 36 in, For Duct Shape Not Applicable, Free Area 8.5 sq ft, Overall Width 42 in, Frame Material Thickness 0.8 in, Overall Length 5 3/4 in, Connection Type Not Applicable, Frame Depth 3 in