30"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 31.75"w x 17.75"h] 18" Round Duct Pipe Measuring 6" in diameter for

Measuring 6" in diameter for the duct opening

This versatile guard features air circulating ports on all four sides to allow proper airflow

+ Product Details Size - 24"w X 16"h X 2"d (for duct opening measurement only)

+ Product Details Size - 25"w X 20"h is the size for the duct opening measurement only

also referred to as T-Bar or Lay-in system

30"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 31.75"w x 17.75"h] 18" Round Duct Pipe Measuring 6" in diameter for+ Product Details Size 30"w X 16"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 31. 75" Width X 17. 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