10"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Black [Outer Dimensions 11.75"w x 11.75"h] Grilles + Product Details Size –

+ Product Details Size – 8" x 20" or 20" x 8" is the size for the duct opening measurement only

+ Product Details Size - 8"w X 36"h is the size for the duct opening measurement only

75" Width X 13

actual front end outer dimensions are approximately 2" wider

10"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Black [Outer Dimensions 11.75"w x 11.75"h] Grilles + Product Details Size –+ Product Details Size 10"w X 10"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 11. 75" Width X 11. 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