The design and materials of open corner windows and doors vary depending on the manufacturer. Western Window Systems, the manufacturer in charge of the windows of Malibu Crest, uses tempered glass as a default for open corner products due to its greater strength than regular glass. At the open corner of a window, manufacturers will typically simply butt the two panes of glass together. In this case, however, the two sheets of insulated glass are joined in a 90-degree wedge shape, creating a seamless connection, with silicon inserted between the two to seal the unit. For their open corner multi-slide doors, the frames and design are equally dramatic: with a unique extrusion attached to the end of one panel, the adjacent panel sliding in at a 90-degree angle simply nestles in smoothly.