12"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 13.75"h] w25h25 Actual Filter Size – 33

Actual Filter Size – 33 3/4"w x 15 3/4" x 1"

+ Product Details Size - 18"w X 32"h is the size for the duct opening measurement only

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

+ Product Details Size - 36"w X 32"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 20 5/8" width X 24 5/8" height

12"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 13.75"h] w25h25 Actual Filter Size – 33+ Product Details Size 12"w X 12"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 13. 75" Width X 13. 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