22"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 23.75"w x 21.75"h] Compatible With Duct 8in + Product Details Size –

+ Product Details Size – 20" x 36" or 36" x 20" is the size for the duct opening measurement only

+ Product Details Size – 10" x 24" or 24" x 10" is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 28" OR 28" x 18" duct opening (measured at the opening)

Installation is simple

22"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 23.75"w x 21.75"h] Compatible With Duct 8in + Product Details Size –+ Product Details Size 22"w X 20"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 23. 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