SIYN Sport Bluetooth 4.0 Neck Band Headphone with Mic and FM Stream Music Player (Black) Long-term wearing comfort and soft touch feeling ergonomic earpiece design Powerful bass to boost motivation, perfectly noise isolating in-ear to create an ideal music to sport atmosphere Rain and sweat resistant, anti-slip, ideal for crossfit, running, jogging, dancing, exercises Bluetooth 4.0 headphones compatible with your smartphone and any other Bluetooth enabled mobile devices Bluetooth multipoint technology allows connection of 2 devices simultaneously, in addition, support FM function