I do not know how to really explain the missing part, but basically you need a sensor wire, then one end of the sensor wire plugs in to the sensor port on the ESC the the other end is plugged in to a special cord (not shown in your picture) then with that plugged then on the other end of that cord you will plug the little plug (not sure what to call it the thing that is at the end of your servos, escs, transponders.) then that will plug into your programmer box. Then turn on your ESC and you should be controlling the power box. Hope this made sense.