8"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 29.75"h] Grille + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 8" x 20" or 20" x 8" duct opening (measured at the opening)

+ Product Details Size - 10"w X 4"h is the size for the duct opening measurement only

+ Product Details Size – 12" x 20" or 20" x 12" is the size for the duct opening measurement only

+ Product Details Size – 16" x 24" or 24" x 16" is the size for the duct opening measurement only

8"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 29.75"h] Grille + Product Details Perfect Fit+ Product Details Size 8"w X 28"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 9. 75" Width X 29. 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