Product Material: This Attic Vent Cover is made of aluminum alloy material that the manufacturer has well tested. It provides good rust and corrosion resistance in any weather conditions, ensuring long-lasting durability and reliability.Size: Total Size: 300x300x8mm / 11.8"x11.8"x0.32", Mounting Hole Distance: 142mm, 285mm / 5.6",11.2"45 Angled Louvered: It features a slanted louver design, which effectively prevents rainwater from entering the interior and keeps it dryUse Screws to Install: This Attic Vent Cover needs screws(Not Included in the Package) for easy installation. It is also easy to install, and you can mount it on the wall with screws in just a few minutes.Mesh Screen Inside: The back is equipped with a mesh cover, which effectively prevents sandstone from entering.