Dayton Louver Damper,Adjustable,60H x 60W 20UA32

63 In.H 63 In.W Drnbl Extrd Alu Combo Dmpr, Louver Type Combination, Frame Type Flanged, Outside Height 59 1/2 in, Outside Width 59 1/2 in, Rough Opening Height 60 in, Rough Opening Width 60 in, Louver Maximum Intake 12,972 cfm, Maximum Exhaust 18,550 cfm, Flange Width 1 1/2 in, Free Area 11.6 sq ft, Beginning Point of Water Penetration 1,118 fpm, Maximum Air Velocity 3000 fpm, Blade Angle 45 Degrees , Material Aluminum, Inside Height 58 1/2 in, Inside Width 57 3/4 in, Number of Blades 12