... noise and power consumption. 6,capacitance microphone input,suit for lapel-microphone and heading-microphone.and so on. Applicationteacher,tourist guide ... temperature -10°C-45°C4,service time 10hours.5,microphone capacitance signal directivity.6,power supply 6v/800mA charger ... ,black,blue,white,sliver white,and so on.Comfort head-microphone headset. Protection in blister.Stand wear and tear waistband ...