51 In.H 33 In.W Drnbl Extrd Alu Intake Louver Louver Type Stationary Blade Frame Type Flanged Frame Depth 4 in Mounting Style Surface Mount Outside Height 47 1/2 in Outside Width 29 1/2 in Rough Opening Height 48 in Rough Opening Width 30 in Louver Maximum Intake 5 117 cfm Maximum Exhaust 7 317 cfm Maximum Outside Width 32 1/2 in Minimum Outside Width 32 1/2 in Flange Width 1 1/2 in Free Area 5.3 sq ft Beginning Point of Water Penetration 1 031 fpm Maximum Air Velocity 3500 fpm