28"w X 32"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 29.75"w x 33.75"h] Fixed Blades with Damper actual front end outer dimensions

actual front end outer dimensions are approximately 16 5/8" width X 14 5/8" height

+ Product Details Size - 20"w X 16"h is the size for the duct opening measurement only

+ Product Details Size - 8"w X 12"h X 2"d (for duct opening measurement only)

+ Product Details Size – 16" x 18" or 18" x 16" is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 8" or 8" x 12" duct opening (measured at the opening)

28"w X 32"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 29.75"w x 33.75"h] Fixed Blades with Damper actual front end outer dimensions+ Product Details Size 28"w X 32"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 29. 75" Width X 33. 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