Louver Damper Adjustable 54H x 48W

56.5 In.H 50.5 In.W Drnbl Extrd Alu Combo Dmpr Louver Type Combination Frame Type Flanged Outside Height 53 1/2 in Outside Width 47 1/2 in Rough Opening Height 54 in Rough Opening Width 48 in Louver Maximum Intake 9 018 cfm Maximum Exhaust 12 896 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 52 1/2 in Inside Width 45 3/4 in Number of Blades 11