Special short straight track, length 41mm.
Equivalent to Hornby R610 and Bachmann 36-610 short straight track.
This track section is one quarter the length of a standard straight and is sometimes required to extend a track to complete a connection when curved points are used to form a crossover. If you look at the Peco Setrack diagram the ST-203 can be seen at the right-hand end of the lowest straight track section where it joins the curve, allowing for the use of the curved point in this curve further to the right on the diagram.