36"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 37.75"w x 19.75"h] 18" Round Duct Pipe actual front end outer dimensions

actual front end outer dimensions are approximately 10 5/8" width X 16 5/8" height

our damper is designed to perfectly align with your setup

+ Product Details Size – 25"w X 6"h is the size for the duct opening measurement only

+ Product Details Size – 10"w X 4"h is the size for the duct opening measurement only

+ Product Details Size - 16"w X 24"h is the size for the duct opening measurement only

36"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 37.75"w x 19.75"h] 18" Round Duct Pipe actual front end outer dimensions+ Product Details Size 36"w X 18"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 37. 75" Width X 19. 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