This tone generator and probe are practical tools. They apply for installing network and checking objects. The tone generator emits a single signal or multiple frequency signals and has two single test cartridges and a 4 p test joint. When wires are bounded and hidden in the wall or are imbedded by a barrier while you are using the tone generator, the tone signal which is sent by the main frame is very easy to test with the probe. The continuity of a wire, a fault of the wire, the polarity of the circuit, a network or the working voltage of the modular cable can be tested by this group tester. The pathway of the circuit and detail position can be judged by the pilot light and the tone of the speaker.