16"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - White [Outer Dimensions 17.75"w x 17.75"h] 10in diameter + Product Details Size -

+ Product Details Size - 4" Diameter is the size for the duct opening measurement only

with actual outer dimensions of 30

+ Product Details Size - 16"w X 24"h X 2"d (for duct opening measurement only)

actual front end outer dimensions are approximately 26 5/8" width X 26 5/8" height

+ Product Details Size - 26"w X 4"h is the size for the duct opening measurement only

16"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - White [Outer Dimensions 17.75"w x 17.75"h] 10in diameter + Product Details Size -+ Product Details Size 16"w X 16"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 17. 75" Width X 17. 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