8"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 29.75"h] 10" Round Duct Pipe + Product Details Size -

+ Product Details Size - 8"w X 4"h is the size for the duct opening measurement only

Actual Filter Size – 23 3/4"w x 19 3/4" x 1"

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

+ Product Details Size – 32"w X 24"h is the size for the duct opening measurement only

8"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 29.75"h] 10" Round Duct Pipe + Product Details Size -+ Product Details Size 8"w X 28"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 9. 75" Width X 29. 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