14"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 15.75"w x 19.75"h] 8in diameter 4" X 10" Is The

4" X 10" Is The Size For The Duct Opening (floor/vent hole) Measurement Only

For 10" duct opening

The lightweight yet rigid construction ensures durability without sacrificing ease of handling

Actual Filter Size – 21 3/4"w x 35 3/4" x 1"

+ Product Details Size - 18"w X 6"h is the size for the duct opening measurement only

14"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 15.75"w x 19.75"h] 8in diameter 4" X 10" Is The+ Product Details Size 14"w X 18"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 15. 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