12" x 8", White, Gable Louver Flange Center, Conforms to Federal Specification QQ-5775A, Type 1, Class 4 ASTM A-527, Meets FHA Codes, 28 Gauge Galvanized Steel, 1 Piece Construction With A 2" Thick Frame, 1/8" Galvanized Wire Mesh Prevents Entry From Birds & Large Insects.