14"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 15.75"w x 19.75"h] 8in diameter + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 8" x 12" or 12" x 8" duct opening (measured at the opening)

actual front end outer dimensions are approximately 24 5/8" width X 10 5/8" height

+ Product Details Size - 8"w X 18"h X 2"d (for duct opening measurement only)

+ Product Details Size - 10"w X 24"h X 2"d (for duct opening measurement only)

look no further than HVAC Premium

14"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 15.75"w x 19.75"h] 8in diameter + Product Details Perfect Fit+ Product Details Size 14"w X 18"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 15. 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