Louver Damper Adjustable 24H x 54W

26.5 In.H 56.5 In.W Drnbl Extrd Alu Combo Dmpr Louver Type Combination Frame Type Flanged Outside Height 23 1/2 in Outside Width 53 1/2 in Rough Opening Height 24 in Rough Opening Width 54 in Louver Maximum Intake 4 034 cfm Maximum Exhaust 5 769 cfm Flange Width 1 1/2 in Free Area 3.6 sq ft Beginning Point of Water Penetration 1 118 fpm Maximum Air Velocity 3 000 fpm Blade Angle 45 Degrees Material Aluminum Inside Height 22 1/2 in Inside Width 51 3/4 in Number of Blades 4