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 Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 16" x 18" OR 18" X 16" duct opening (measured at the opening)

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

Actual Front End Outer Dimensions Are 14" Width X 4" Height - SEE IN DESCRIPTION HOW TO MEASURE A GRILLE

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

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 Perfect Fit+ 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