10"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 11.75"w x 21.75"h] w26h26 Actual Filter Size – 17

Actual Filter Size – 17 3/4"w x 23 3/4" x 1"

These are built heavy duty for installation into brick and cement walls

+ Product Details Size - 18"w X 14"h is the size for the duct opening measurement only

+ Product Details Size – 18"w X 28"h is the size for the duct opening measurement only

+ Product Details Size – 12"w X 32"h is the size for the duct opening measurement only

10"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 11.75"w x 21.75"h] w26h26 Actual Filter Size – 17+ Product Details Size 10"w X 20"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 11. 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