26"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 27.75"w x 29.75"h] 6" Round Duct Pipe these heavy-duty louvers are ideal

these heavy-duty louvers are ideal for use in attics

+ Product Details Size – 6"w X 14"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 8" x 20" or 20" x 8" duct opening (measured at the opening)

+ Product Details Size – 20"w X 30"h is the size for the duct opening measurement only

Durable stamped steel construction ensures long-lasting performance

26"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 27.75"w x 29.75"h] 6" Round Duct Pipe these heavy-duty louvers are ideal+ Product Details Size 26"w X 28"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 27. 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