20"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 23.75"h] Fixed Blades + Product Details Size –

+ Product Details Size – 36"w X 6"h is the size for the duct opening measurement only

+ Product Details Size - 12"w X 30"h is the size for the duct opening measurement only

+ Product Details Size – 8" x 24" or 24" x 8" is the size for the duct opening measurement only

actual front end outer dimensions are approximately 32 5/8" width X 16 5/8" height -

Complies with industry standards of USA: ASTM D-882

20"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 23.75"h] Fixed Blades + Product Details Size –+ Product Details Size 20"w X 22"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 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