10"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 11.75"w x 17.75"h] 12in diameter + Product Details Size -

+ Product Details Size - 36"w X 26"h is the size for the duct opening measurement only

+ Product Details Size - 16"w X 18"h is the size for the duct opening measurement only

high-impact clear plastic for long-lasting performance

+ Product Details Perfect Fit & Easy Sizing - Designed for a 26" x 12" OR 12" x 26" duct opening (measured at the opening)

10"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 11.75"w x 17.75"h] 12in diameter + Product Details Size -+ Product Details Size 10"w X 16"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 11. 75" Width X 17. 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