6"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 7.75"w x 17.75"h] Ceiling 24"w X 6"h Is The

24"w X 6"h Is The Size For The Duct Opening Measurement Only

if your hole is 20" wide by 14" tall

+ Product Details Size - 8"w X 34"h X 2"d (for duct opening measurement only)

+ Product Details Size - 30"w X 34"h is the size for the duct opening measurement only

6"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 7.75"w x 17.75"h] Ceiling 24"w X 6"h Is The+ Product Details Size 6"w X 16"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 7. 75" Width X 17. 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