12"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 27.75"h] w26h26 + Product Details Size – AD-S-230-10x10 Width_8in Actual Filter Size 25

+ Product Details Size – 30"w X 18"h is the size for the duct opening measurement only

+ Product Details Size – 30"w X 12"h is the size for the duct opening measurement only

Heavy Gauge Steel – Heavier gauge than needed

actual front end outer dimensions are approximately 26 5/8" width X 10 5/8" height -

+ Product Details Size - 14"w X 22"h is the size for the duct opening measurement only

12"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 13.75"w x 27.75"h] w26h26 + Product Details Size – AD S 230 10x10 Width_8in Actual Filter Size 25 + Product Details Size – 30"w X 18"h is the size for the duct opening measurement only + Product Details Size – 30"w X 12"h is the size for the duct opening measurement only