... to the rear portion of the helmet Bluetooth headset, a total of 4 device, the otherCable connection ... only to the rear portion of the helmet Bluetooth headset, the other a wired connection 1 way device ... "+" health is common, short by adjust the headset volume, long press music pause.At the end of ... and volume "and" common, short by adjust the headset volume, long press end number redial.Six, increase ...