20"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 15.75"h] 18" Round Duct Pipe The design eliminates noise and

The design eliminates noise and prevents louvers from vibrating

+ Product Details Size - 36"w X 32"h is the size for the duct opening measurement only

container) return

making it ideal for preventing tampering or unauthorized adjustments

+ Product Details Size - 3" Diameter is the size for the duct opening measurement only

20"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 15.75"h] 18" Round Duct Pipe The design eliminates noise and+ Product Details Size 20"w X 14"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 15. 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