20"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 11.75"h] Copper Coil + Product Details Size -

+ Product Details Size - 10"w X 28"h is the size for the duct opening measurement only

+ Product Details Size – 10" x 24" or 24" x 10" is the size for the duct opening measurement only

Ideal for Walls & Ceilings: Designed for seamless installation in standard 16" X 4" duct openings

+ Product Details Perfect Fit & Easy Sizing - Designed for a 8" x 34" or 34" x 8" duct opening (measured at the opening)

With a 8" diameter for the duct opening measurement

20"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 11.75"h] Copper Coil + Product Details Size -+ Product Details Size 20"w X 10"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 11. 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