20"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Brown [Outer Dimensions 21.75"w x 21.75"h] 8in diameter + Product Details Size –

+ Product Details Size – 18"w X 25"h is the size for the duct opening measurement only

+ Product Details Size – 34"w X 16"h is the size for the duct opening measurement only

+ Product Spec Sheet Aluminum Return Filter Grille Spec Sheet

Achieve superior control over your indoor airflow for a more comfortable space

actual front end outer dimensions are approximately 12 5/8" width X 38 5/8" height

20"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Brown [Outer Dimensions 21.75"w x 21.75"h] 8in diameter + Product Details Size –+ Product Details Size 20"w X 20"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 21. 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