8"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - White [Outer Dimensions 9.75"w x 9.75"h] Width_20in + Product Details Size –

+ Product Details Size – 4"w X 10"h or 10"w X 4"h is the size for the duct opening measurement only

14" Diameter Is The Size For The Duct Opening Measurement Only

Actual Filter Size – 17 3/4"w x 25 3/4" x 1"

+ Product Details Outer dimensions: 11

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

8"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - White [Outer Dimensions 9.75"w x 9.75"h] Width_20in + Product Details Size –+ Product Details Size 8"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 9. 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