16"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 13.75"h] 1-Way 75"H – fits a 24" RG1620AL Quality Packaging carefully packaged 8 Feet Long

75"H – fits a 24" X 6" duct opening

+ Product Details Size - 18"w X 30"h is the size for the duct opening measurement only

+ Product Details Size – 36"w X 26"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 34 5/8" width X 32 5/8" height

16"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 17.75"w x 13.75"h] 1 Way 75"H – fits a 24" RG1620AL Quality Packaging carefully packaged 8 Feet Long 75"H – fits a 24" X 6" duct opening + Product Details Size 18"w X 30"h is the size for the duct opening measurement only