48 In.H 36 In.W Non-Drnbl GSteel Modulr Louver, Louver Type Stationary Blade, Frame Type Hat Channel, Frame Depth 4 in, Mounting Style Flush Mount, Outside Height 47 1/2 in, Outside Width 35 1/2 in, Rough Opening Height 48 in, Rough Opening Width 36 in, Louver Maximum Intake 4,099 cfm, Maximum Exhaust 5,855 cfm, Maximum Outside Width 35 1/2 in, Minimum Outside Width 35 1/2 in, Flange Width Not Applicable, Free Area 5.2 sq ft, Beginning Point of Water Penetration 709 fpm