18"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 9.75"h] 12in diameter + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 14" x 36" OR 36" X 14" duct opening (measured at the opening)

Actual Front End Outer Dimensions Are 16" Diameter

+ Product Details Size - 32"w X 26"h is the size for the duct opening measurement only

+ Product Details Size - 16"w X 16"h X 2"d (for duct opening measurement only)

with actual outer dimensions of 30

18"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 9.75"h] 12in diameter + Product Details Perfect Fit+ Product Details Size 18"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 19. 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