Intake Louver, Fixed, Drainable, 18H x 18W, DAYTON, Mfr# 20UA08

21 In.H 21 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 17 1/2 in, Rough Opening Height 18 in, Rough Opening Width 18 in, Louver Maximum Intake 1,034 cfm, Maximum Exhaust 1,478 cfm, Maximum Outside Width 20 1/2 in, Minimum Outside Width 20 1/2 in, Flange Width 1 1/2 in, Free Area 1 sq ft, Beginning Point of Water Penetration 1,031 fpm, Maximum Air Velocity 3500 fpm