Lets you quickly and accurately  measure the voltage in each cell up to from 2S --> 5S.  Simply plug in the balancing tap into the pins. Its that simple!  Measure your lipo packs while they are still strapped into your aircraft. 

See the voltage Display in action below. Notice how the pack it is measuring is slightly out of balance. 

The example below is reading as follows

CELL 3 = 4.21V
CELL 2 = 4.27V
CELL 1 = 4.22V