22"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 23.75"w x 29.75"h] 18" Diameter + Product Details Size –

+ Product Details Size – 18"w X 32"h is the size for the duct opening measurement only

+ Product Details Size – 30" x 36" or 36" x 30" is the size for the duct opening measurement only

+ Product Details Size - 24"w X 18"h X 2"d (for duct opening measurement only)

only measure the "hole" in the wall/duct

22"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 23.75"w x 29.75"h] 18" Diameter + Product Details Size –+ Product Details Size 22"w X 28"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 23. 75" Width X 29. 75" Height Weather and Pest Proof These louvers are especially designed to prevent water from entering your home, and with a built in back 1 2" mesh they also protect you from annoying rodents like mice, rats, birds, and squirrels High Quality Aluminum The premium durable aluminum will never rust and it will never