Combination Louver Damper 36x24

36 In.H 24 In.W Drnbl Extrd Alu Combo Dmpr Louver Type Combination Frame Type Hat Channel Outside Height 35 1/2 in Outside Width 23 1/2 in Rough Opening Height 36 in Rough Opening Width 24 in Louver Maximum Intake 1 531 cfm Maximum Exhaust 2 406 cfm Flange Width Not Applicable Free Area 2.3 sq ft Beginning Point of Water Penetration 1 118 fpm Maximum Air Velocity 3 500 fpm Blade Angle 45 Degrees Material Aluminum Inside Height 34 1/2 in Inside Width 21 3/4 in Number of Blades 7