8"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 11.75"h] 12" Diameter Engineered for easy installation

Engineered for easy installation

+ Product Details Perfect Fit & Easy Sizing - Designed for a 22" x 20" OR 20" x 22" duct opening (measured at the opening)

+ Product Details Size - 20"w X 18"h is the size for the duct opening measurement only

Actual Filter Size – 13 3/4"w x 13 3/4" x 1"

8"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 11.75"h] 12" Diameter Engineered for easy installation+ Product Details Size 8"w X 10"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 9. 75" Width X 11. 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