I finally needed this cable locator/continuity tester after having had it since mid 2017. I needed to identify wires from a bundle that came pre-wired to (two) new garage door openers I'm installing. The TONE tracer works very well and you can choose between warble (factory setting) and steady tones by sliding the switch next to the 9V battery. The CONTINUITY FUNCTION will not beep, but the LED will illuminate when there is continuity. This block is a great deal and works well. (The more expensive cable toner Tacklife CT01, which I also bought at the same time, does not work at all, although it says that it was tested under number 3). As a general rule, get this, NOT the CT01.