16"w X 30"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 31.75"h] w18h18 and with a built-in back

and with a built-in back 1/2" mesh they also protect you from annoying rodents like mice

actual front end outer dimensions are approximately 27

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 8" OR 8" X 18" duct opening (measured at the opening)

R Value Rating of Insulation - R3

+ Product Details Size – 34"w X 14"h is the size for the duct opening measurement only

16"w X 30"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 31.75"h] w18h18 and with a built-in back+ Product Details Size 16"w X 30"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 17. 75" Width X 31. 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