26"w X 6"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 27.75"w x 7.75"h] Aluminum Adjustable Curved Blade you can attain the diameter

you can attain the diameter of the vent

By means of the smooth surface

this coil exceeds the required 700 PSI for R410 with a pressure rating of 2300 to 6500 PSI

+ Product Details Size – 22" x 28" or 28" x 22" is the size for the duct opening measurement only

26"w X 6"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 27.75"w x 7.75"h] Aluminum Adjustable Curved Blade you can attain the diameter+ Product Details Size 26"w X 6"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 27. 75" Width X 7. 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