12"w X 24"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 25.75"h] w28h28 + Product Details Size -

+ Product Details Size - 4"w X 34"h is the size for the duct opening measurement only

and Centralized Air Ducted Units

actual front end outer dimensions are 15

But they are also the most visible representation of you air system

at predicted low air motion 35 fpm in the zone of occupancy

12"w X 24"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 25.75"h] w28h28 + Product Details Size -+ Product Details Size 12"w X 24"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 13. 75" Width X 25. 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