headset feature a button on the microphone pod that has two functions.
Firstly, it will let you end the call
by pressing it briefly. Secondly, if your phone supports it,
press and hold to activate voice dialling.
If you set up your phone for
auto-answer when the headset is plugged in, then you'll be able
to answer, end and make voice-dialled calls without needing to
press any buttons on your phone.