12"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 19.75"h] ceiling actual front end outer dimensions

actual front end outer dimensions are approximately 27 5/8" width X 14 5/8" height

Design – Heavy gauge steel

+ Product Details Size - 24"w X 36"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 38 5/8" width X 16 5/8" height -

Actual Filter Size – 7 3/4"w x 33 3/4" x 1"

12"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 19.75"h] ceiling actual front end outer dimensions+ Product Details Size 12"w X 18"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 13. 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