Louver Damper Adjustable 24H x 60W

26.5 In.H 62.5 In.W Drnbl Extrd Alu Combo Dmpr Louver Type Combination Frame Type Flanged Outside Height 23 1/2 in Outside Width 59 1/2 in Rough Opening Height 24 in Rough Opening Width 60 in Louver Maximum Intake 4 509 cfm Maximum Exhaust 6 447 cfm Flange Width 1 1/2 in Free Area 4 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 57 3/4 in Number of Blades 4