True to scale, extra fine modeling, accurate to prototype in every aspect. Very specialized, purist oriented scale type. Code-87 wheels are considered correct for P64 modeling, scale exact in detail as to the prototype wheels being modeled, wheel tread diameters of; 26, 28, 33, 36 and 40 for rolling stock and tender applications are available. Even the gauge, "track spread", has to be custom designed for locomotive/rolling stock wheels, of the code-87 variety, to negotiate tight radiuses, custom hand laid turnouts and crossovers.