20"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 9.75"h] Aluminum - Cube Core 75"H – fits a 20"

75"H – fits a 20" X 10" duct opening

+ Product Details Size – 24" x 32" or 32" x 24" is the size for the duct opening measurement only

+ Product Details Size – 8"w X 20"h is the size for the duct opening measurement only

Actual Filter Size – 21 3/4"w x 7 3/4" x 1"

For 10" Round Duct Opening - Spiral or Flex

20"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 9.75"h] Aluminum - Cube Core 75"H – fits a 20"+ Product Details Size 20"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 9. 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 wear