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 Actual Filter Size – 9

Actual Filter Size – 9 3/4"w x 25 3/4" x 1"

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

this grille seamlessly drops into the designated place

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

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 Actual Filter Size – 9+ 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