14"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 15.75"w x 15.75"h] with filter + Product Details Size -

+ Product Details Size - 40"w X 20"h is the size for the duct opening measurement only

The first number in a grille size

875" width X 13

actual front end outer dimensions are approximately 8

14"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 15.75"w x 15.75"h] with filter + Product Details Size -+ Product Details Size 14"w X 14"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 15. 75" Width X 15. 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