Louver Damper Adjustable 42H x 54W

44.5 In.H 56.5 In.W Drnbl Extrd Alu Combo Dmpr Louver Type Combination Frame Type Flanged Outside Height 41 1/2 in Outside Width 53 1/2 in Rough Opening Height 42 in Rough Opening Width 54 in Louver Maximum Intake 7 697 cfm Maximum Exhaust 11 006 cfm Flange Width 1 1/2 in Free Area 6.9 sq ft Beginning Point of Water Penetration 1 118 fpm Maximum Air Velocity 3000 fpm Blade Angle 45 Degrees Material Aluminum Inside Height 40 1/2 in Inside Width 51 3/4 in Number of Blades 9