Finally, returned this headset to B2C portal and collected it accordingly. Waiting for refund soon. This microphone quality is not good ( 2.4Ghz with notebook-Win10 and BT 5.0 with Android phone) and keeps coming out the "dot-matrix line printer" kind of noise after record-voice-replay. Have 2x Mpow 415 2.4Ghz headset without such microphone issue like this KZ GP20 did.