WM-B12

The WM-B12 is a low-cost playback Walkman built around a basic mechanism, a manual tape selector, and a compact plastic body powered by two AA batteries. A carry clip and minimal controls kept the machine easy to use, with the whole design focused on inexpensive and reliable everyday cassette playback instead of any kind of sonic enhancement or advanced transport behavior. It was one of the clearer plain playback machines in Sony's 1989 lineup.

The B12 is not significant because it introduced anything new, but because it suggests Sony was still maintaining a clean, simple entry point into the Walkman family. Machines like this kept cassette everyday and reachable even as the rest of the line became more segmented and feature-driven. It was a baseline product in the best sense.