Combination Louver Damper 48x36

48 In.H 36 In.W Drnbl Extrd Alu Combo Dmpr Louver Type Combination Frame Type Hat Channel Outside Height 47 1/2 in Outside Width 35 1/2 in Rough Opening Height 48 in Rough Opening Width 36 in Louver Maximum Intake 3 369 cfm Maximum Exhaust 5 294 cfm Flange Width Not Applicable Free Area 5.2 sq ft Beginning Point of Water Penetration 1 118 fpm Maximum Air Velocity 3 500 fpm Blade Angle 45 Degrees Material Aluminum Inside Height 46 1/2 in Inside Width 33 3/4 in