6"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 7.75"w x 19.75"h] Compatible with Duct 8" + Product Details Size –

+ Product Details Size – 10"w X 18"h is the size for the duct opening measurement only

75"H – fits a 16" X 4" duct opening

you can attain the diameter of the vent

+ Product Details Size – 36"w X 10"h is the size for the duct opening measurement only

Its elegant look and fine finish and the natural warmth of oak wood

6"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 7.75"w x 19.75"h] Compatible with Duct 8" + Product Details Size –+ Product Details Size 6"w X 18"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 7. 75" Width X 19. 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 wear