.6mm square belt used for replacement, tape sounded good when tested (no warping or tapping sounds and timing appeared good)

The recording functionality appeared to work since it recorded blank sounds over the cassette when tested, it just didn't pick up my voice because I don't have a wired microphone to for testing.

The Vintage Sony WM-F200II Recording Walkman is a portable cassette player made in Japan. This black Sony Walkman features AM/FM capabilities and an headphone jack for audio output. With a new belt installed, it is in working condition and ready to enjoy your cassette tape collection on-the-go.