36"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 37.75"w x 23.75"h] flat stamped steel + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 12" OR 12" X 18" duct opening (measured at the opening)

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

+ Product Details Size - 10"w X 22"h is the size for the duct opening measurement only

+ Product Details High Quality - Aluminum housing on the outside and on the inside for the best insulation value

36"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 37.75"w x 23.75"h] flat stamped steel + Product Details Perfect Fit+ Product Details Size 36"w X 22"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 37. 75" Width X 23. 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