16"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 21.75"h] Insulated Line 75" Width X 27

75" Width X 27

+ Product Details Size – 10"w X 16"h is the size for the duct opening measurement only

Actual Filter Size – 35 3/4"w x 7 3/4" x 1"

Think of the diameter as a straight line from one end to the other

16"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 21.75"h] Insulated Line 75" Width X 27+ Product Details Size 16"w X 20"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 17. 75" Width X 21. 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