8"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Brown [Outer Dimensions 9.75"w x 9.75"h] Powder Coated + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 12" OR 12" X 18" duct opening (measured at the opening)

only measure the "hole" in the wall/duct

Actual Filter Size – 24 3/4"w x 17 3/4" x 1"

Actual Filter Size – 24 3/4"w x 24 3/4" x 1"

Tailored for Your Needs: Specifically suited for 24x24 lay-in diffusers

8"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Brown [Outer Dimensions 9.75"w x 9.75"h] Powder Coated + Product Details Perfect Fit+ Product Details Size 8"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 9. 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