I purchased this with Motorola Earpiece with Boom Microphone. I couldn't first make them work together but the manual has an important detail:
Do not plug the headset when the radio is on. If you do that, then the radio immediately starts transmitting and does not stop no matter what you do until the head set is unplugged.
To use the headset, turn off the radio, plug in the headset, open the radio. When you do that it goes into VOX mode, it will start transmitting in about one second of your speaking. If you press PTT button, the VOX will be cancelled, and if you want to enable VOX again just turn off and on the radio.