36"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 37.75"w x 11.75"h] Grilles Measuring 4" in diameter for

Measuring 4" in diameter for the duct opening

+ Product Details Size – 4"w X 12"h is the size for the duct opening measurement only

+ Product Details Size - 22"w X 10"h is the size for the duct opening measurement only

6" x 6" - opening (vent hole - Neck Size) dimension - actual size is approx 2" wider

+ Product Details Size – 50"w X 20"h is the size for the duct opening measurement only

36"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 37.75"w x 11.75"h] Grilles Measuring 4" in diameter for+ Product Details Size 36"w X 10"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 37. 75" Width X 11. 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