12"w X 6"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 7.75"h] White actual front end outer dimensions

actual front end outer dimensions are approximately 18 5/8" width X 38 5/8" height

This versatile diffuser is adaptable to various airflow needs

Ideal for Walls & Ceilings: Designed for seamless installation in standard 14" X 10" duct openings

actual front end outer dimensions are approximately 27 5/8" width X 22 5/8" height

+ Product Details Size – 20"w X 20"h is the size for the duct opening measurement only

12"w X 6"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 7.75"h] White actual front end outer dimensions+ Product Details Size 12"w X 6"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 13. 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