14 x 18 gable louver 28 gauge galvanized steel, 1 piece construction with a 2 thick frame 18 galvanized wire mesh, 110 sq in net free vent area Ventilates 229 sq ft The rough opening is 1414 x 1814 Nailing flange with 78 reveal for stucco construction Conforms to Federal Spec QQ5775A, type 1, class 4 ASTM A527 and Meets FHA codes