Louver Damper, Adjustable, 48H x 54W, DAYTON, Mfr# 20UC31

50.5 In.H 56.5 In.W Drnbl Extrd Alu Combo Dmpr, Louver Type Combination, Frame Type Flanged, Outside Height 47 1/2 in, Outside Width 53 1/2 in, Rough Opening Height 48 in, Rough Opening Width 54 in, Louver Maximum Intake 9,082 cfm, Maximum Exhaust 12,988 cfm, Flange Width 1 1/2 in, Free Area 8.1 sq ft, Beginning Point of Water Penetration 1,118 fpm, Maximum Air Velocity 3000 fpm, Blade Angle 45 Degrees , Material Aluminum, Inside Height 46 1/2 in, Inside Width 51 3/4 in, Number of Blades 10