The absolute safe identification is based on polarity and signal magnitude of the DC pulse (up to 100 A) coming from the transmitter, which is picked up by the receiver and a clip-on probe. The transmitter can operate on 120 VAC or internal battery (up to 50 hrs run time). The entire system functions without user adjustments and will, under no circumstances, provide a false positive identification. The standard combination kit (for HV & LV cables) includes a 6" flexible clip-on probe, and two touch sensors for all your applications where a clip on cannot be used.