48 in Backdraft Damper / Wall Shutter, 51-1/2 in x 51-1/2 in, DAYTON, Mfr# 53DR19

54 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 2, Maximum Air Velocity 2500 fpm, Overall Height 54 in, Rough Opening Diameter 51 1/2 in, Rough Opening Shape Square, Fits Fan Diameter 48 in, For Duct Shape Not Applicable, Free Area 14.8 sq ft, Overall Width 54 in, Frame Material Thickness 0.8 in, Overall Length 5 3/4 in, Connection Type Not Applicable, Frame Depth 3 in