36 In.H 48 In.W Non-Drnbl Alu Modular 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 47 1/2 in Rough Opening Height 36 in Rough Opening Width 48 in Louver Maximum Intake 4 099 cfm Maximum Exhaust 5 855 cfm Maximum Outside Width 47 1/2 in Minimum Outside Width 47 1/2 in Flange Width Not Applicable Free Area 5.4 sq ft Beginning Point of Water Penetration 709 fpm