18"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 27.75"h] Return Grille Actual Filter Size – 7

Actual Filter Size – 7 3/4"w x 31 3/4" x 1"

and Centralized Air Ducted Units

+ Product Details Size – 16"w X 6"h is the size for the duct opening measurement only

the actual front end outer dimensions are 7" in diameter

+ Product Details Size - 24"w X 8"h X 2"d (for duct opening measurement only)

18"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 27.75"h] Return Grille Actual Filter Size – 7+ Product Details Size 18"w X 26"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 19. 75" Width X 27. 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