30"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 31.75"w x 23.75"h] 18" Diameter + Product Details Size –

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

They seamlessly integrate into sheet rock plaster frame ceilings as well

+ Product Details Perfect Fit & Easy Sizing - Designed for a 14" x 12" or 12" x 14" duct opening (measured at the opening)

+ Product Details Perfect Fit & Easy Sizing - Designed for a 8" x 32" or 32" x 8" duct opening (measured at the opening)

+ Product Details Size - 20"w X 25"h is the size for the duct opening measurement only

30"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 31.75"w x 23.75"h] 18" Diameter + Product Details Size –+ Product Details Size 30"w X 22"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 31. 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