PECO Streamline Z CODE 60 Flexible Track with Wooden Sleeper. This is Z Gauge Code 60, a small-scale flexible track. With a gauge of just 6.5mm and a model scale of 1.5mm/1ft, it is currently the smallest practical size for building a working model railway. If you want to model big landscapes where the trains are dwarfed by the scenery and yet keep it to a manageable size, Z gauge could be the answer. Technical Specification: Length: 610mm.