50ft 3.5mm Stereo Plug/Jack M/F Cable - Black The 3.5mm (1/8") stereo TRS connector is more commonly known as the Headphone Jack on portable mp3 players and mobile phones. This cable features a male 3.5mm stereo (TRS) plug on one end and a female stereo (TRS) jack on the other end, each with molded connector housings and strain relief boots. The cable is ideal for extending the reach of a fixed length 3.5mm stereo cable, such as the cable on a pair of earphones.