The PDF™ Hinged Patio Door System features tough fiberglass panels that resist dents and dings better than comparably priced steel products. Plus, the PDF comes standard with a HP adjustable sill and is available in a variety of styles and lite choices. It is shipped fully assembled and backed by a full system 10-year limited warranty. PDF fiberglass patio door systems are a good deal for homes of all shapes, styles and sizes.