6"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 7.75"w x 9.75"h] 18in diameter actual front end outer dimensions

actual front end outer dimensions are approximately 32 5/8" width X 8 5/8" height

actual front end outer dimensions are approximately 20 5/8" width X 30 5/8" height

Design – Heavier gauge than needed

Actual Filter Size – 33 3/4"w x 23 3/4" x 1"

6"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 7.75"w x 9.75"h] 18in diameter actual front end outer dimensions+ Product Details Size 6"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 7. 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