18"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 29.75"h] Adjustable Return + Product Details Size –

+ Product Details Size – 16"w X 16"h is the size for the duct opening measurement only

+ Product Details Size – 20"w X 40"h is the size for the duct opening measurement only

actual front end outer dimensions are 15

+ Product Details Size – 18" x 32" or 32" x 18" is the size for the duct opening measurement only

Ring Base Design – Allows for easy installation without removing the thermostat

18"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 29.75"h] Adjustable Return + Product Details Size –+ Product Details Size 18"w X 28"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 19. 75" Width X 29. 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