16"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 9.75"h] sidewall 6" x 6" - opening

6" x 6" - opening (vent hole - Neck Size) dimension - actual size is approx 2" wider

Powder-Coat Finish – Never rust

75"H – fits a 8" X 6" duct opening

Actual Filter Size – 27 3/4"w x 33 3/4" x 1"

+ Product Description Maximize HVAC efficiency with our aluminum eggcrate return air filter grille

16"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 9.75"h] sidewall 6" x 6" - opening+ Product Details Size 16"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 17. 75" Width X 9. 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 wear