4PANEL DESCRIPTION3ANTENNA CONNECTOR(p. 2)Connect the supplied antenna.SPEAKER/MIC JACK [SP/MIC](p. 23)Connect the optional speaker microphone (HM-213) here.PTT SWITCH [PTT]Hold down to transmit: release to receive. (p. 11)POWER KEY []Hold down to turn power ON or OFF.CHANNEL 16 KEY [16 9]