Fisher M-Scope PF-8000 E Cable Resistance Fault Locator Parts or Repair *** Parts or Repair No Returns *** *** Please ONLY Purchase if you know what you are doing with this item*** Thanks The Fisher M-Scope PF-8000E is a portable cable resistance fault locator. It is designed for use in demanding environments, ensuring safety and security for any event. The Fisher M-Scope PF-8000E works by evaluating the time difference between the acoustic signal (speed of sound) and the electromagnetic (nearly the speed of light) impulse of the shock discharge. When the shortest time difference is indicated, the exact fault location is revealed.