10"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 11.75"w x 9.75"h] 10in diameter + Product Details Size –

+ Product Details Size – 25"w X 32"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 34" x 12" Or 12" x 34" duct opening (measured at the opening)

font-size: 16px

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

10"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 11.75"w x 9.75"h] 10in diameter + Product Details Size –+ Product Details Size 10"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 11. 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