The JSD Testphone Cable Tracing Kit AM4/TG4 is used typically by an engineer working alone to identify the termination point and/ or path of metallic wiring over much shorter distances and shallower locations than with the Tester 132J. The cable tracing kit can perform continuity and polarity checks. The AM4 gives both an audio and visual indication on wires identified. The complete kit comprises a Tone Generator (TG4), an Inductive Probe Amplifier (AM4) and a carrying case. All parts can also be ordered separately. An RJ11 or other plugs can be fitted on request.