18"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 29.75"h] Return Ideal for Walls & Ceilings:

Ideal for Walls & Ceilings: Designed for seamless installation in standard 20" X 10" duct openings

actual front end outer dimensions are approximately 24 5/8" width X 27 5/8" height

you can watch this informative video tutorial: How to Measure Your Vent Hole Before Ordering a Grille

crafted from heavy gauge steel for unparalleled durability

they seamlessly integrate into your space

18"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 29.75"h] Return Ideal for Walls & Ceilings:+ Product Details Size 18"w X 28"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 19. 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