Dayton Intake Louver,42x42 45C678

42 In.H 42 In.W Drnbl Extrd Alu Intake Louver, Louver Type Stationary Blade, Frame Type Hat Channel, Frame Depth 4 in, Mounting Style Recess Mount, Outside Height 41 1/2 in, Outside Width 41 1/2 in, Rough Opening Height 42 in, Rough Opening Width 42 in, Louver Maximum Intake 3,734 cfm, Maximum Exhaust 4,875 cfm, Maximum Outside Width 41 1/2 in, Minimum Outside Width 41 1/2 in, Flange Width Not Applicable, Free Area 6.5 sq ft, Beginning Point of Water Penetration 1,031 fpm