28"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 29.75"w x 13.75"h] 18" Diameter + Product Details Size –

+ Product Details Size – 20"w X 32"h is the size for the duct opening measurement only

High Quality – High quality solid stamped steel with counter-sunk screw holes (screws included) and no sharp edges

+ Product Details Size – 18" x 20" or 20" x 18" is the size for the duct opening measurement only

40"w X 16"h Is The Size For The Duct Opening Measurement Only

Say goodbye to vibrating louvers - this grille ensures a quiet

28"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 29.75"w x 13.75"h] 18" Diameter + Product Details Size –+ Product Details Size 28"w X 12"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 29. 75" Width X 13. 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