Louver Damper, Adjustable, 54H x 54W, DAYTON, Mfr# 20UA31

57 In.H 57 In.W Drnbl Extrd Alu Combo Dmpr, Louver Type Combination, Frame Type Flanged, Outside Height 53 1/2 in, Outside Width 53 1/2 in, Rough Opening Height 54 in, Rough Opening Width 54 in, Louver Maximum Intake 10,221 cfm, Maximum Exhaust 14,616 cfm, Flange Width 1 1/2 in, Free Area 9.1 sq ft, Beginning Point of Water Penetration 1,118 fpm, Maximum Air Velocity 3000 fpm, Blade Angle 45 Degrees , Material Aluminum, Inside Height 52 1/2 in, Inside Width 51 3/4 in, Number of Blades 11