Highly compatible bluetooth 4.0, which compatible with IOS iPhone or Android smartphones with clear and mellow music play. Be able to connect 2 devices at the same time. Magnet attached design, stick 2 ear-plugs together when they are standby, like a necklace, prevent cable tangles and fall down from neck. Dump energy can be displayed when it was connected with Apple ios. Built-in microphone with noise reduction, intelligently recognize the noise and sound, clear talking experience.