20"w X 34"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 35.75"h] w26h26 + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 36" or 36" x 12" duct opening (measured at the opening)

Both lines taped together every 18in for easier handling & installation

actual front end outer dimensions are approximately 26 5/8" width X 28 5/8" height

the second number represents the height

20"w X 34"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 35.75"h] w26h26 + Product Details Perfect Fit+ Product Details Size 20"w X 34"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 35. 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