12"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 21.75"h] Compatible With Duct 8in Actual Filter Size – 25

Actual Filter Size – 25 3/4"w x 27 3/4" x 1"

+ Product Details Size – 10" x 36" or 36" x 10" is the size for the duct opening measurement only

Marked circles for cutout

helping to maintain consistent temperature settings

+ Product Details Size – 36"w X 12"h is the size for the duct opening measurement only

12"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 21.75"h] Compatible With Duct 8in Actual Filter Size – 25+ Product Details Size 12"w X 20"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 13. 75" Width X 21. 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