Using the Elekon Batscanner Stereo takes your enjoyment of bat detecting to a whole new level. The effect of having stereo microphones, one on each side of the unit, and headphones is to give a totally immersive experience of hearing the bats flitting and flying all around you. You really have to try it to believe how exciting it is. This heterodyne detector is also very easy to use, because it automatically tunes itself to the frequency of the bats it hears and displays the frequency on an lcd display, so you can differentiate between different types of bat without any manual tuning. This unit comes supplied with stereo headphones and batteries ready fitted.