WM-EX406

The WM-EX406 took a similar midrange playback formula and compressed it into a thinner plastic body, putting more emphasis on pocketability while keeping auto-reverse, Mega Bass, AVLS, and standard battery operation. It is clearly built for users who still wanted a slimmer portable without stepping into the higher, more fully equipped branches of the EX line. The feature set remained restrained.

This one reads more as a packaging move than a technical one, and that is perfectly fine. By 1998, many late Walkman were being differentiated as much by form and carry feel as by mechanics. The EX406 is a good example of that quieter kind of refinement.