18"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Brown [Outer Dimensions 19.75"w x 19.75"h] Aluminum Adjustable Curved Blade Actual Filter Size – 31

Actual Filter Size – 31 3/4"w x 5 3/4" x 1"

Ideal for Walls & Ceilings: Designed for seamless installation in standard 18" X 4" duct openings

+ Product Description Upgrade your HVAC system with our 8" Round Air Vent Supply Grille

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

18"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Brown [Outer Dimensions 19.75"w x 19.75"h] Aluminum Adjustable Curved Blade Actual Filter Size – 31+ Product Details Size 18"w X 18"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 19. 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