16"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 27.75"h] 18" Round Duct Pipe actual front end outer dimensions

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

+ Product Details Size – 30"w X 34"h is the size for the duct opening measurement only

+ Product Details Size - 22"w X 4"h is the size for the duct opening measurement only

that will overlap at wall joint

actual front end outer dimensions are approximately 34 5/8" width X 12 5/8" height -

16"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 27.75"h] 18" Round Duct Pipe actual front end outer dimensions+ Product Details Size 16"w X 26"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 17. 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