16"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 13.75"h] Curved Blade Steel + Product Details Size -

+ Product Details Size - The listed 8" diameter refers specifically to the size of the duct opening

please note that the total outer dimensions of the grille measure 12" in diameter

actual front end outer dimensions are approximately 28 5/8" width X 10 5/8" height

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 22" OR 22" x 20" duct opening (measured at the opening)

16"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 13.75"h] Curved Blade Steel + Product Details Size -+ Product Details Size 16"w X 12"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 17. 75" Width X 13. 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