Intake Louver Fixed Drainable 18H x 36W

21 In.H 39 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 35 1/2 in Rough Opening Height 18 in Rough Opening Width 36 in Louver Maximum Intake 2 274 cfm Maximum Exhaust 3 252 cfm Maximum Outside Width 38 1/2 in Minimum Outside Width 38 1/2 in Flange Width 1 1/2 in Free Area 2 sq ft Beginning Point of Water Penetration 1 031 fpm Maximum Air Velocity 3500 fpm