Louver Damper Adjustable 42H x 42W

45 In.H 45 In.W Drnbl Extrd Alu Combo Dmpr Louver Type Combination Frame Type Flanged Outside Height 41 1/2 in Outside Width 41 1/2 in Rough Opening Height 42 in Rough Opening Width 42 in Louver Maximum Intake 5 886 cfm Maximum Exhaust 8 417 cfm Flange Width 1 1/2 in Free Area 5.3 sq ft Beginning Point of Water Penetration 1 118 fpm Maximum Air Velocity 3 000 fpm Blade Angle 45 Degrees Material Aluminum Inside Height 40 1/2 in Inside Width 39 3/4 in Number of Blades 9