10"w X 6"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 11.75"w x 7.75"h] 18in diameter actual front end outer dimensions

actual front end outer dimensions are approximately 16 5/8" width X 20 5/8" height

+ Product Description Maximize your home’s airflow with this premium Air Supply Grille air supply grille

actual front end outer dimensions are approximately 38 5/8" width X 14 5/8" height -

actual front end outer dimensions are approximately 24 5/8" width X 27 5/8" height

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

10"w X 6"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 11.75"w x 7.75"h] 18in diameter actual front end outer dimensions+ Product Details Size 10"w X 6"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 11. 75" Width X 7. 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