16"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Black [Outer Dimensions 17.75"w x 17.75"h] fixed bar Actual Filter Size – 27

Actual Filter Size – 27 3/4"w x 9 3/4" x 1"

+ Product Details Size - 18"w X 32"h is the size for the duct opening measurement only

+ Product Details Size – 16"w X 26"h is the size for the duct opening measurement only

Equipped with a locking eight-tumbler key system

Actual Filter Size – 21 3/4"w x 35 3/4" x 1"

16"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Black [Outer Dimensions 17.75"w x 17.75"h] fixed bar Actual Filter Size – 27+ 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