To say this unit really works well is an understatement. I connect my interphone to my motorcycle GPS via bluetooth (a BMW Navigator III [made by Garmin]). At the same time I connect my cell phone(Motorola V505) to the GPS via bluetooth. My GPS automatically switches between the voice GPS directions and cell calls.A buddy and I both have interphones in our motorcycle helmets and we communicate on the road via bluetooth using the intercom feature. The range is spec'd as 500ft, but we find the functional distance closer to 1000ft. One can switch back and forth on the fly between the bike to bike intercom and the GPS/Cell Phone using the multifunction button on the interphone.Battery life is good for a whole day's riding in the intercom mode. In the standby mode the battery life is definately many days, because I sometimes forget to shut off the interphone.This is the best device of its kind I have ever seen. It gets rid of CB radios for bike to bike communication, with a constant hot mike (no keying required). Many kudos also go to my BMW GPS Navigator III and its ability to manage the Cell Phone and GPS directions. It also displays the Cell Phone address book, shows the ID of incoming calls, etc. etc.