8"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 19.75"h] Brown + Product Details Size –

+ Product Details Size – 26"w X 30"h is the size for the duct opening measurement only

this grille enhances air circulation

actual front end outer dimensions are approximately 26 5/8" width X 38 5/8" height -

+ Product Details Size – 14" x 18" or 18" x 14" is the size for the duct opening measurement only

Actual Filter Size – 19 3/4"w x 25 3/4" x 1"

8"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 19.75"h] Brown + Product Details Size –+ Product Details Size 8"w X 18"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 9. 75" Width X 19. 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