32"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 33.75"w x 15.75"h] Powder-Coat Actual Filter Size – 21

Actual Filter Size – 21 3/4"w x 17 3/4" x 1"

+ Product Details Size – 20" x 24" or 24" x 20" is the size for the duct opening measurement only

and the second number represents the height

+ Product Details Size – 6" x 18" or 18" x 6" is the size for the duct opening measurement only

32"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 33.75"w x 15.75"h] Powder-Coat Actual Filter Size – 21+ Product Details Size 32"w X 14"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 33. 75" Width X 15. 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