Louver Damper Adjustable 54H x 24W

56.5 In.H 26.5 In.W Drnbl Extrd Alu Combo Dmpr Louver Type Combination Frame Type Flanged Outside Height 53 1/2 in Outside Width 23 1/2 in Rough Opening Height 54 in Rough Opening Width 24 in Louver Maximum Intake 4 209 cfm Maximum Exhaust 6 018 cfm Flange Width 1 1/2 in Free Area 3.8 sq ft Beginning Point of Water Penetration 1 118 fpm Maximum Air Velocity 3 000 fpm Blade Angle 45 Degrees Material Aluminum Inside Height 52 1/2 in Inside Width 21 3/4 in Number of Blades 11