I forgive not 5 stars because of the price in my opinion, but fails too high, because it is in this version no Etuit case and a USB dongle, as you can see the part in YouTube videos. So here's another version that you should know. I also have a Plantronics M55, with which I am quite happy, but ... I have done 2 tests, even calls and at the same wash your hands under running water and then and held there a call Accu-Handstaubsauger about 20 cm from the headset. In both cases, you could add my voice to the Sennheiser still pretty good understanding (!), With the Planronics the voice was chopped off some passing urine test and the vacuum cleaner test could no longer understand me. The price of the Sennheiser is so maybe justified for extreme situations, for most other situations (especially if you have little background noise) extends the Plantronics M55 slack off (!) And is still very reasonably priced. And the voice quality of the M55 is no background noise almost the same as the Sennheiser so outstanding. In my ear, the M55 keeps even without ironing quite good, the Sennheiser that is not so well and I have to share a security the earhook, which is a shame ;-(
