28"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 29.75"w x 13.75"h] Outdoor Vent Covers + Product Details Size –

+ Product Details Size – 18"w X 12"h is the size for the duct opening measurement only

Actual Filter Size – 24 3/4"w x 13 3/4" x 1"

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

+ Product Details Perfect Fit & Easy Sizing - Designed for a 34" x 22" Or 22" x 34" duct opening (measured at the opening)

28"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 29.75"w x 13.75"h] Outdoor Vent Covers + Product Details Size –+ Product Details Size 28"w X 12"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 29. 75" Width X 13. 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