Unfortunately unusable despite many good characteristics

The headset has some several plus points:
- Absolutely easy pairing did, not even have to read the manual
- Comfortable to wear
- Good voice quality, good sound quality
- Both left and right to carry thanks to adjustable bracket
- Easy to feel buttons on the ear (answer, volume, On / Off)
- After switching fast reconnect (about 3 seconds I would guess)
- Battery lasts extremely long (several hours of talk), remaining capacity (High, Medium, Low) will be announced at power

Unfortunately there is a downside, which makes the device for me and probably a number of other potential users completely uninteresting:
- The device amplifies rustling, crackling noises or bright incredibly violent. The interlocutors rips his headset from the head or throw the phone away in order not to suffer hearing loss. When I read during the call Zeitung (rustling), a coffee umrühre, something sliding into a plastic holder, a granola bar unpack, Tesa abrolle or whatever - at the slightest sound from this category fall the interlocutor ears off. Tested with several devices.
- Bite: The volume knob goes in only one direction, whosoever wants quieter must have maximum it off (which is then also announced accordingly loud "BeepBeep: VOLUME MAXIMUM!"), Then the volume will start again at the lowest level

Conclusion: If no call is in absolute silence, but by the way would do office or housework, will have no use for the device.