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] Ceiling this filter grille never rusts

this filter grille never rusts and withstands long-term use in any environment

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 6" OR 6" X 18" duct opening (measured at the opening)

+ Product Details Size – 10"w X 8"h is the size for the duct opening measurement only

Smooth powder-coated white finish for a sleek look and scratch resistance

75"H – fits a 18" X 10" duct opening

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] Ceiling this filter grille never rusts+ 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