34"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 35.75"w x 23.75"h] Compatible with Duct 8" Design – This airflow control

Design – This airflow control component are made to connect to a drop ceiling lay-in diffuser grille

+ Product Details Size - 12"w X 20"h is the size for the duct opening measurement only

order a 14x20 grille

+ Product Details Perfect Fit & Easy Sizing - Designed for a 6" x 12" or 12" x 6" duct opening (measured at the opening)

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

34"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 35.75"w x 23.75"h] Compatible with Duct 8" Design – This airflow control+ Product Details Size 34"w X 22"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 35. 75" Width X 23. 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