24 in Backdraft Damper / Intake Shutter, 25 in x 25 in, DAYTON, Mfr# 4YN17

26.75 In.H-W 4.5 In.L Alu Intake Shutter Dampr, For Nominal Duct Diameter Not Applicable, Frame Material Aluminum, Number of Panels 1, Maximum Air Velocity 2250 fpm, Overall Height 26 3/4 in, Rough Opening Diameter 25 in, Rough Opening Shape Square, Fits Fan Diameter 24 in, For Duct Shape Not Applicable, Free Area 3.2 sq ft, Overall Width 26 3/4 in, Frame Material Thickness 0.1 in, Overall Length 4 1/2 in, Connection Type Not Applicable, Frame Depth 1 5/8 in, Rough Opening Length 25 in