The TC18 5th Gen Mini View Camera System FR350 Module Set includes a 350mm precision focusing slide rail and 6-layer bellows. For users of the TC18 5th Gen Mini View Camera System, this module set allows for an upgrade in camera length, making it suitable for large format lenses with a longer focal length, or achieving a greater macro magnification ratio. Changing the module set requires no tools and can be quickly accomplished through two knobs. With the addition of the FR350 module set, you essentially have the equivalent of two machines of different specifications. If you only need an extended version of the TC18 5th Gen Mini View Camera System, this can be achieved by ordering the FR350 module set, along with the FS1 and RS1 modules. They can be assembled into a complete machine.