Whoever the genius Garmin Zumo 660 as used as a biker Biker Navi should use the possible Bluetooth transmission option. But for this you need a Bluetooth headset! Most offered devices are designed more for use in connection with a mobile phone and therefore do not provide enough volume on the headphones. So I have the Bluetooth headset by Nokia (BH 103) or the more expensive Sony Ericsson MW600 purchased Disappointing! With loud wind noise under the helmet there is nothing to understand. Not so with the Jabra BT3030: Not only that, the Garmin Zumo 660 connects quickly with the Jabra, finally the volume is completely ok. The battery lasts at least 4 hours and even played mp3 music by Zumo land in stereo quality in the Bikers ears. Those who wish can be to get better headphones, Jabra has a standard mini-jack KH: Perfect. These lines for all bikers who want to learn the hard way that what I had to pay to spare. Incidentally, 2 Jabra at a Zumo (for the rider) does not work, although the Jabra mindests 15 yards receiving far.