16"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 37.75"h] Ceiling Its locking eight-tumbler mechanism and

Its locking eight-tumbler mechanism and supplied key safeguard your thermostat from tampering

+ Product Details Size - 18"w X 24"h is the size for the duct opening measurement only

+ Product Details Size – 18" x 36" or 36" x 18" is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 26" x 10" OR 10" x 26" duct opening (measured at the opening)

+ Product Details Size – 12" x 12" is the size for the duct opening measurement only

16"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 37.75"h] Ceiling Its locking eight-tumbler mechanism and+ Product Details Size 16"w X 36"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 17. 75" Width X 37. 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