8"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 27.75"h] w18h18 + Product Details Size –

+ Product Details Size – 20"w X 6"h is the size for the duct opening measurement only

6"w X 6"h Is The Size For The Duct Opening Measurement Only

+ Product Details Size - 28"w X 4"h is the size for the duct opening measurement only

Design – These are specially sized to fit into all drop ceilings

8"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 27.75"h] w18h18 + Product Details Size –+ Product Details Size 8"w X 26"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 9. 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 wear