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] Filter Grille + Product Details Size –

+ Product Details Size – 18" x 30" or 30" x 18" is the size for the duct opening measurement only

For 14" Round Duct Opening - Spiral or Flex

+ Product Details Perfect Fit & Easy Sizing - Designed for a 16" x 28" OR 28" X 16" duct opening (measured at the opening)

and a control lever designed for seamless operation

padding: 14px 14px

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] Filter Grille + Product Details Size –+ 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