Z-Scale model trains are the smallest of the common model trains available. Each train is 1/220th the size of its real equivalent! The most common commerically manufactured scales are, from biggest to smallest:
G (1:25)
O (1:48)
S (1:64)
HO (1:87)
N (1:160)
Z (1:220)
Smaller scales that are not yet as prolific are the ZZ-Scale (1:300) and T-Scale (1:450). The latter is currently the smallest scale train on the market.
Compared to other model train scales, Z-Scale trains allow for really efficient use of space when building train modules (standard area of track layouts). Much more detail can be packed into each module when the trains takes up less space and require less room to turn.
We take full advantage of this at McCormick-Stillman, adding tremendous detail into our projects. We have already created interesting exhibits for you to see, thanks to the hard work of our team.