Louver Damper Adjustable 36H x 48W

39 In.H 51 In.W Drnbl Extrd Alu Combo Dmpr Louver Type Combination Frame Type Flanged Outside Height 35 1/2 in Outside Width 47 1/2 in Rough Opening Height 36 in Rough Opening Width 48 in Louver Maximum Intake 5 787 cfm Maximum Exhaust 8 275 cfm Flange Width 1 1/2 in Free Area 5.2 sq ft Beginning Point of Water Penetration 1 118 fpm Maximum Air Velocity 3 000 fpm Blade Angle 45 Degrees Material Aluminum Inside Height 34 1/2 in Inside Width 45 3/4 in Number of Blades 7