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

+ Product Details Size - 12" X 12" is the size for the duct opening measurement only

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

+ Product Details Perfect Fit & Easy Sizing - Designed for a 36" x 32" OR 32" x 36" duct opening (measured at the opening)

+ Product Details Size – 18" x 26" or 26" x 18" is the size for the duct opening measurement only

resisting rust and wear while adding a sleek

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