20"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 21.75"h] 6in diameter 180 Degrees Double Direction Adjustable

180 Degrees Double Direction Adjustable - Fins Are Manually Adjustable Individually for Optimal Air Distribution

actual front end outer dimensions are approximately 25

Close For Winter To Prevent The Cold

And The Cooler Air From Outside WIll Flow In From The Bottom

Actual Filter Size – 27 3/4"w x 27 3/4" x 1"

20"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 21.75"h] 6in diameter 180 Degrees Double Direction Adjustable+ Product Details Size 20"w X 22"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 23. 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