20"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 37.75"h] Compatible with Duct 8" Universal Fit – Measures 3-7/8"

Universal Fit – Measures 3-7/8" wide x 3-1/2" high x 3" deep

actual front end outer dimensions are approximately 16 5/8" width X 24 5/8" height

+ Product Details Size - 36"w X 34"h is the size for the duct opening measurement only

Slim Sliding Metal Damper To Control and Adjust Airflow

20"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 37.75"h] Compatible with Duct 8" Universal Fit – Measures 3-7/8"+ Product Details Size 20"w X 36"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 37. 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