functional device, but some imperfections

The handsfree adapts well to most devices emitting bluetooth. It lets you listen to music, watch videos (for sound). The calls are relatively well (to note, however, some problems listening on the part of the speaker, especially with the wind).
Holding the headset holds well for me in the ears, although at first it may feel it is too loose. Note that I practice regularly cycling, it also happens that I run: he never fell!

Good ergonomics (the action buttons are well placed)

However two major issues to note:
_The Interference when listening to music, the music sometimes cut several fractions of a second (I think it has ever happened on the video - '). But no interference on calls
_A Manufacturing defect or design at neck level that causes after several months of use false contacts manifested mainly by non-full loads or sudden extinction of the device: from my side, several devices have had this problem, fortunately supported by the guarantee.