Intake Louver Fixed Drainable 18H x 24W

21 In.H 27 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 23 1/2 in Rough Opening Height 18 in Rough Opening Width 24 in Louver Maximum Intake 1 447 cfm Maximum Exhaust 2 069 cfm Maximum Outside Width 26 1/2 in Minimum Outside Width 26 1/2 in Flange Width 1 1/2 in Free Area 1.3 sq ft Beginning Point of Water Penetration 1 031 fpm Maximum Air Velocity 3500 fpm