20"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 15.75"h] 6" Diameter + Product Details Size -

+ Product Details Size - 12"w X 4"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 28 5/8" width X 14 5/8" height

16" x 3" Aluminum Spiral Duct Air Vent Grille Cover - Fully Adjustable Double Deflection HVAC Air Supply

+ Product Details Size - 14"w X 12"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 16" x 24" OR 24" X 16" duct opening (measured at the opening)

20"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 15.75"h] 6" Diameter + Product Details Size -+ Product Details Size 20"w X 14"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 15. 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