8"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 23.75"h] Supply Grille + Product Details Size –

+ Product Details Size – 20"w X 24"h is the size for the duct opening measurement only

this flex duct decreases the pressure loss and provides a more hygienic environment

Rigid Gauge Steel

actual front end outer dimensions are 9

+ Product Details Outer dimensions: 21

8"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 23.75"h] Supply Grille + Product Details Size –+ Product Details Size 8"w X 22"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 9. 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 wear