The Amprobe AT-6010T Advanced Wire Tracer makes it easier and safer to locate Energized and De-energized wires, breakers and fuses. When the Transmitter is connected to the circuit, the Receiver (Sold separately) easily detects the signal in the wires or cables behind walls, ceilings and floors. The Transmitter works on Energized and De-energized circuits up to 600 V AC/DC in Category I through Category III electrical environments, allowing for work directly on an energized circuit without the need to take equipment offline. The Transmitter also features high signal mode for general tracing and a loop mode designed specifically for locating shorts, as well as two optimal tracing frequencies that are automatically activated based on the detected voltage.