8"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Brown [Outer Dimensions 9.75"w x 17.75"h] Aluminum - Cube Core actual front end outer dimensions

actual front end outer dimensions are approximately 10 5/8" width X 30 5/8" height

if your hole is 20" wide by 14" tall

actual front end outer dimensions are approximately 14 5/8" width X 22 5/8" height

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

8"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Brown [Outer Dimensions 9.75"w x 17.75"h] Aluminum - Cube Core actual front end outer dimensions+ Product Details Size 8"w X 16"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 9. 75" Width X 17. 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