18"w X 24"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - White [Outer Dimensions 19.75"w x 25.75"h] Outdoor Vent Covers actual front end outer dimensions

actual front end outer dimensions are approximately 21 5/8" width X 31 5/8" height

actual front end outer dimensions are approximately 36 5/8" width X 22 5/8" height

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

+ Product Details Size - 4"w X 34"h is the size for the duct opening measurement only

Ideal for Walls & Ceilings: Designed for seamless installation in standard 12" X 8" duct openings

18"w X 24"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - White [Outer Dimensions 19.75"w x 25.75"h] Outdoor Vent Covers actual front end outer dimensions+ Product Details Size 18"w X 24"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 19. 75" Width X 25. 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