20"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 37.75"h] Width_20in + Product Details Size -

+ Product Details Size - 16"w X 22"h X 2"d (for duct opening measurement only)

Tailored for Your Needs: Specifically suited for 24x24 lay-in diffusers

+ Product Details Size - 28"w X 4"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 42 5/8" width X 22 5/8" height -

875" width X 12" height

20"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 37.75"h] Width_20in + Product Details Size -+ Product Details Size 20"w X 36"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 37. 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