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] Compatible with Duct 6" actual front end outer dimensions

actual front end outer dimensions are 19" Width X 11" Height

+ Product Details Size - 20"w X 36"h is the size for the duct opening measurement only

Actual Filter Size – 27 3/4"w x 19 3/4" x 1"

+ Product Details Size - 4"w X 18"h is the size for the duct opening measurement only

+ Product Details Size - 6"w X 10"h X 2"d (for duct opening measurement only)

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] Compatible with Duct 6" 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