12"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 9.75"h] Powder-Coat + Product Details Size -

+ Product Details Size - 8"w X 34"h is the size for the duct opening measurement only

+ Product Details Size - 26"w X 14"h is the size for the duct opening measurement only

background-color: #5296DD

actual front end outer dimensions are approximately 38 5/8" width X 20 5/8" height -

+ Product Details Size – 24"w X 24"h is the drop ceiling HVAC supply grille size - for T-Bar lay-in

12"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 9.75"h] Powder-Coat + Product Details Size -+ Product Details Size 12"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 13. 75" Width X 9. 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 wear