There's one small device, but yet, here the quality of the recording, it is very good. At this price, I expected a quality and lower volume, it is found that this mic is very good (not great but if you want better, put it over your pocket). And to top it all, I find it rather class.
The 3 positions are very similar (this may be the location of the mic that does this) but I will not hear big differences.