26"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 27.75"w x 21.75"h] w12h12 + 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)

+ Product Details Size - 32"w X 8"h is the size for the duct opening measurement only

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

+ Product Details Size – 20" x 22" or 22" x 20" is the size for the duct opening measurement only

Actual Filter Size – 33 3/4"w x 13 3/4" x 1"

26"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 27.75"w x 21.75"h] w12h12 + Product Details Perfect Fit+ Product Details Size 26"w X 20"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 27. 75" Width X 21. 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