16"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Black [Outer Dimensions 17.75"w x 17.75"h] Aluminum + Product Details Size - RG1620AL Quality Packaging carefully packaged 8 Feet Long

+ Product Details Size - 25"w X 18"h is the size for the duct opening measurement only

+ Product Details Size – 25"w X 14"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 26 5/8" width X 12 5/8" height

Seamless Installation: Designed to fit seamlessly into a 24 by 24 inch opening

16"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh Black [Outer Dimensions 17.75"w x 17.75"h] Aluminum + Product Details Size RG1620AL Quality Packaging carefully packaged 8 Feet Long + Product Details Size 25"w X 18"h is the size for the duct opening measurement only + Product Details Size – 25"w X 14"h is the size for the duct opening measurement only