18"w X 6"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 7.75"h] Adjustable Return Actual Filter Size – 7

Actual Filter Size – 7 3/4"w x 19 3/4" x 1"

+ Product Details Size - 4"w X 22"h is the size for the duct opening measurement only

actual front end outer dimensions are 19" Width X 19" Height

This versatile diffuser is available in 1-way

you can quickly adjust airflow for year-round comfort

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