The Sony WM-20 is a portable cassette player that was introduced by Sony in the early 1980s. Designed for ease of use and portability, the WM-20 features a compact and lightweight design, making it an ideal device for music lovers on the go. The cassette player comes equipped with a built-in speaker, allowing users to enjoy their tapes without the need for headphones. Additionally, it has a headphone jack for private listening. The device offers a simple control interface, including play, stop, rewind, and fast forward buttons, ensuring intuitive operation. The WM-20 also has a battery compartment that supports standard AA batteries, providing long-lasting playback and convenience during travel. A notable feature of the WM-20 is its exceptional sound quality, which was a significant selling point at the time of its release.