18"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 15.75"h] Aluminum Actual Filter Size – 23 4 X 12 Is CRFG2028 Width_14in

Actual Filter Size – 23 3/4"w x 29 3/4" x 1"

+ Product Details Size - 6"w X 18"h is the size for the duct opening measurement only

With its compact size and high-quality materials

rust-free aluminum

+ Product Details Size – 10" x 26" or 26" x 10" is the size for the duct opening measurement only

18"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 19.75"w x 15.75"h] Aluminum Actual Filter Size – 23 4 X 12 Is CRFG2028 Width_14in Actual Filter Size – 23 3 4"w x 29 3 4" x 1" + Product Details Size 6"w X 18"h is the size for the duct opening measurement only