Louver Damper Adjustable 48H x 54W

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