Bluetooth handsfree kit helmet headset bluetooth version bluetooth 41 call functions answerend button end call redialing number of controllable devices 2 power supplies li ion rechargeable assembly type helmet audio functions fm radio with rds hi fi stereo voice control digital signal processing dsp schwanenhalsmikrofon gooseneck microphone rds function radio mute full duplex bluetooth profiles a2dp avrcp aghfp included in delivery mini usb cable microp