Shure I3c Integrated Sound Isolating Earphones with Dual Connector WideBand MicroDriver Technology plus VoicePort Mic and Multi-function Control Switch Dual connectors means your earphones are plugged into both cell phone and portable music device at the same time Loud and clear calls, clear and enjoyable music VoicePort  inline microphone filters out background noise Shure makes audio equipment - microphones, earphones, mixers, etc. that are used by professional musicians the world over