18"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 21.75"h] Color_R-4.2 Yellow + Product Details Size -

+ Product Details Size - 24"w X 18"h X 2"d (for duct opening measurement only)

+ Product Details Size - 30"w X 25"h is the size for the duct opening measurement only

+ Product Details Size - 10"w X 32"h is the size for the duct opening measurement only

The back is completely insulated

18"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 21.75"h] Color_R-4.2 Yellow + Product Details Size -+ Product Details Size 18"w X 20"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 19. 75" Width X 21. 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