Features 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.
If there's one drawback, it would be that the cable is a little on the short side for in-car use - you might want to consider a Bluetooth headset instead. But then this is about a quarter of the cost ...