This cable locator operates acoustically and provides a quick solution for finding de-energized lines in home installations, checking telephone lines, identifying individual cables or conductors, or performing continuity tests. With the transmitter and tone generator, a carrier signal is modulated onto an electrical conductor, which you can track using the receiver and amplifier, as well as the built-in speaker or through a headphone jack. Additionally, a dial on the receiver allows you to adjust the sensitivity for optimal identification. When connected to a telephone socket via the RJ-11 plug, the LED on the transmitter indicates the status of the active telephone line as "free," "busy," or "ringing." The transmitter also features a continuity test, where the LED lights up brightly when there is continuity and dims as resistance increases.