26"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 27.75"w x 9.75"h] Insulated Line Set + Product Details Size –

+ Product Details Size – 10" x 16" or 16" x 10" is the size for the duct opening measurement only

All of these grills have dampers

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 20" or 20" x 12" duct opening (measured at the opening)

75"H – fits a 18" X 6" duct opening

26"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 27.75"w x 9.75"h] Insulated Line Set + Product Details Size –+ Product Details Size 26"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 27. 75" Width X 9. 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 wear