12"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Black [Outer Dimensions 13.75"w x 13.75"h] w36h36 + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 34" OR 34" x 20" duct opening (measured at the opening)

Ideal for Walls & Ceilings: Designed for seamless installation in standard 14" X 4" duct openings

listed size +1

+ Product Details Size - 26"w X 12"h is the size for the duct opening measurement only

4" X 12" Is The Size For The Duct Opening (floor/vent hole) Measurement Only

12"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Black [Outer Dimensions 13.75"w x 13.75"h] w36h36 + Product Details Perfect Fit+ Product Details Size 12"w X 12"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 13. 75" Width X 13. 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