Intake Louver Fixed Drainable 18H x 54W

21 In.H 57 In.W Drnbl Extrd Alu Intake Louver Louver Type Stationary Blade Frame Type Flanged Frame Depth 4 in Mounting Style Surface Mount Outside Height 17 1/2 in Outside Width 53 1/2 in Rough Opening Height 18 in Rough Opening Width 54 in Louver Maximum Intake 3 515 cfm Maximum Exhaust 5 026 cfm Maximum Outside Width 56 1/2 in Minimum Outside Width 56 1/2 in Flange Width 1 1/2 in Free Area 3.3 sq ft Beginning Point of Water Penetration 1 031 fpm Maximum Air Velocity 3500 fpm