24"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 25.75"w x 19.75"h] Compatible With Duct 6in + Product Details Size –

+ Product Details Size – 18"w X 36"h is the size for the duct opening measurement only

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

Actual Filter Size – 24 3/4"w x 19 3/4" x 1"

actual front end outer dimensions are approximately 18 5/8" width X 18 5/8" height

+ Product Description Ventilate your home or commercial space with our Aluminum Outdoor Weatherproof Louvers

24"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 25.75"w x 19.75"h] Compatible With Duct 6in + Product Details Size –+ Product Details Size 24"w X 18"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 25. 75" Width X 19. 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