18"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 9.75"h] Filter Grille + Product Details Size -

+ Product Details Size - 22"w X 36"h is the size for the duct opening measurement only

+ Product Details Size – 10"w X 36"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 18 5/8" width X 22 5/8" height

and a control lever designed for seamless operation

order a 14x20 grille

18"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 9.75"h] Filter Grille + Product Details Size -+ Product Details Size 18"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 19. 75" Width X 9. 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