36 In.H 24 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 35 1/2 in Outside Width 23 1/2 in Rough Opening Height 36 in Rough Opening Width 24 in Louver Maximum Intake 2 028 cfm Maximum Exhaust 2 897 cfm Maximum Outside Width 23 1/2 in Minimum Outside Width 23 1/2 in Flange Width Not Applicable Free Area 2.5 sq ft Beginning Point of Water Penetration 709 fpm