34"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 35.75"w x 29.75"h] 12" Round Duct Pipe + Product Details Size -

+ Product Details Size - 18"w X 6"h is the size for the duct opening measurement only

+ Product Details Size – 25"w X 14"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 30" x 14" OR 14" x 30" duct opening (measured at the opening)

actual front end outer dimensions are approximately 36 5/8" width X 28 5/8" height

+ Product Details Perfect Fit & Easy Sizing - Designed for a 26" x 20" OR 20" x 26" duct opening (measured at the opening)

34"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 35.75"w x 29.75"h] 12" Round Duct Pipe + Product Details Size -+ Product Details Size 34"w X 28"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 35. 75" Width X 29. 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