Standard Hinged systems can consist of one or more shutter panels hinged in a variety of configurations. Single panels can be individually hinged or two panels may be hinged together in a bi-fold design. Bi-fold on track systems allow up to eight panels to be hinged together. Panels are connected to a top and bottom track. Finally, in a by-pass track system, shutters are not hinged - they slide on top tracks to open and close. This system allows you to cover wide widths, and is a wonderful way to treat sliding doors to match the rest of your windows.