21 In.H 21 In.W Drnbl Extrd Alu Combo Dmpr, Louver Type Combination, Frame Type Flanged, Outside Height 17 1/2 in, Outside Width 17 1/2 in, Rough Opening Height 18 in, Rough Opening Width 18 in, Louver Maximum Intake 779 cfm, Maximum Exhaust 1,114...
21 In.H 21 In.W Drnbl Extrd Alu Combo Dmpr, Louver Type Combination, Frame Type Flanged, Outside Height 17 1/2 in, Outside Width 17 1/2 in, Rough Opening Height 18 in, Rough Opening Width 18 in, Louver Maximum Intake 779 cfm, Maximum Exhaust 1,114...