The voice quality is great, you can understand me very well and I hear my interlocutor also in top quality. Through a regulator for the microphone sensitivity and volume control the headset can be adjusted well. Unlike the M170 model is still a microphone mute switch installed.
The comfort is class. The headset can be with an earhook right "fit to your ear." ;-) I however prefer to use the supplied headband with padded leather shell. The M175 can be converted in accordance with two handles. Especially practical is the headset of course together with a DECT handset with a belt clip.