18"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 23.75"h] Compatible With Duct 10in For 10" Round Duct Opening

For 10" Round Duct Opening - Spiral or Flex

+ Product Details Size – 34" x 36" or 36" x 34" is the size for the duct opening measurement only

24"w X 6"h Is The Size For The Duct Opening Measurement Only

+ Product Details Size – 8" round duct opening

18"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 23.75"h] Compatible With Duct 10in For 10" Round Duct Opening+ Product Details Size 18"w X 22"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 19. 75" Width X 23. 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