KOSS The Plug Black (lifetime)

In 1958, John C. Koss teamed up with engineer Martin Lang Jr. and together they developed the first phonograph player with additional speakers. These were intended to allow the new phonograph to be demonstrated at a Wisconsin audio show. One of the exceptional features of this product was a "privacy" switch that allowed listeners to hear music through plugged-in SP/3 headphones, the world's first. These headphones were intended as an accessory to showcase the exceptional stereo sound that the turntable could deliver. Koss headphones became a worldwide hit in the listening category.