20"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 11.75"h] Aluminum + Product Details Size -

+ Product Details Size - 20"w X 10"h is the size for the duct opening measurement only

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

Great emphasis has been invested in the design of this product to prevent it from kinking in sharp bends & turns and to hold steady and at full diameter in all applications

875" width X 16" height

20"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 11.75"h] Aluminum + Product Details Size -+ Product Details Size 20"w X 10"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 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