... duplex,digital& wireless -distance over 700m -unique technique Hands free 2 way radiotwo way radio Applicable Scope:1. Electric ... Receiver sensitivity is -100dBm7. Voice Frequency: 300Hz ~ 3000Hz8. Earphone : with diameter 2.5 audio plug, microphone and volume adjust9 ... Receiver sensitivity is -100dBm7. Voice Frequency: 300Hz ~ 3000Hz8. Earphone : with diameter 2.5 audio plug, microphone and volume ...