WM-FK5

A compact radio Walkman from Sony's short-lived Widdit series, the FK5 combined an FM/AM tuner with a transparent skeleton body that reacted under blacklight. It relied on basic analog tuning and Mega Bass for sound, housed in an unusually compact chassis with a coiled-cord keychain remote. The design traded advanced tape features for novelty styling and portability.

Positioned as an affordable fashion accessory instead of an audiophile tool, the FK5 targeted younger buyers who wanted a Walkman that doubled as a conversation piece. Sony uses the model to test playful transparent designs in the late cassette era, keeping production simple while giving the radio segment a visual hook that stood out on store shelves.