Sony Walkman EQ SEQ-50 Stereo Graphic Equalizer. Highly collectable rare vintage Sony Walkman EQ. Black. Clean and operational. Used with some slight user marks. Runs on 2x AA batteries. Batteries not included to avoid leaking of the batteries. Made in Japan. Dimensions in cm: 11,5 cm x 8 cm x 2,3 cm Weight: 111,30 grams without 2x AA batteries Located in EU. Buyer is responsible for all taxes and customs duties that may apply. Google: The Sony SEQ-50 graphic equalizer was manufactured and sold between 1983 and 1988, with some sources also indicating an earlier release window from 1982–1987. It is a rare, portable accessory designed for Sony Walkman cassette players, made in Japan and known for its 5-band equalizer and high-quality sound.