Combo Louver Damper, Adj, 23-1/2 H, Alum, DAYTON, Mfr# 5NKH7

18 In.H 21 In.W Drnbl Extrd Alu Combo Dmpr, Louver Type Combination, Frame Type Hat Channel, Outside Height 23 1/2 in, Outside Width 23 1/2 in, Rough Opening Height 24 in, Rough Opening Width 24 in, Louver Maximum Intake 1,005 cfm, Maximum Exhaust 1,444 cfm, Flange Width Not Applicable, Free Area 1.3 sq ft, Beginning Point of Water Penetration 1,118 fpm, Maximum Air Velocity 3,000 fpm, Blade Angle 45 Degrees , Material Aluminum, Inside Height 22 1/2 in, Inside Width 21 3/4 in, Number of Blades 4