18"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 37.75"h] w34h34 + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 16" x 26" OR 26" X 16" duct opening (measured at the opening)

+ Product Details Size – 12" x 36" or 36" x 12" is the size for the duct opening measurement only

Round-neck-to-square-face construction results in 360 degree air diffusion pattern similar to a full round diffuser

excluding the old vent cover

18"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 37.75"h] w34h34 + Product Details Perfect Fit+ Product Details Size 18"w X 36"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 19. 75" Width X 37. 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