20"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 9.75"h] Ceiling Airflow – Improved airflow dynamics

Airflow – Improved airflow dynamics long neck bBody- reduced noise design - integrated spring fasteners

Actual Filter Size – 24 3/4"w x 21 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 16" OR 16" X 18" duct opening (measured at the opening)

+ Product Details Perfect Fit & Easy Sizing - Designed for a 32" x 24" OR 24" x 32" duct opening (measured at the opening)

+ Product Details Size - 14"w X 24"h is the size for the duct opening measurement only

20"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 9.75"h] Ceiling Airflow – Improved airflow dynamics+ Product Details Size 20"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 9. 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 wear