With the largest selection of louver gable end vents and the strongest .019 aluminum construction to last a lifetime. Each attic vent comes with choice of mounting flange, color, size including depth, and screen. Louvers are constructed with a 4-fold front and a double hem back for extra strength. The louver is locked onto a strong rail system for more durability. Slats are spaced for optimal ventilation for each thickness and the best water intrusion protection. After being pop riveted into place, a wind-sheer buffer is applied before the vent trim. Top of the line vent technology for a lifetime attic louver. Also, offering matching aluminum half round window trim sized to fit any arched window. Curved window trim is often forgotten on a project or said, "it cannot be done." We say, "Yes it can!" A round top window only requires 5 measures to ensure a great fit every time. Even the true circle window trim is simple to order.