This window system is manufactured using RAU-FIPRO™, a high-tech material developed by REHAU based on the company’s vast experience with fiber composites for aircraft and Formula 1 race cars. The material is a hybrid fiberglass and vinyl that combines the benefits of both materials without their drawbacks. Like vinyl, it can be extruded in a multi-chambered design and fusion welded. Plus, it provides the high stability, torsional stiffness and static properties of fiberglass. It also has a low thermal expansion ratio.