Dayton Intake Louver,Fixed, Drainable,36H x 24W 20UA10

27 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 35 1/2 in, Outside Width 23 1/2 in, Rough Opening Height 36 in, Rough Opening Width 36 in, Louver Maximum Intake 2,894 cfm, Maximum Exhaust 4,139 cfm, Maximum Outside Width 26 1/2 in, Minimum Outside Width 26 1/2 in, Flange Width 1 1/2 in, Free Area 2.8 sq ft, Beginning Point of Water Penetration 1,031 fpm, Maximum Air Velocity 3500 fpm