This Tone Generator is a very practical tool, which provides a single or dual tone signal, two test leads and a 4-conductor modular cable. It generates a signal from one end and traces the cables from the other by probe, even when cables are in a bundle or hidden in a mess of punch down blocks or wall plates. It is easy to be used to verify cables continuity, pair condition, line polarity and voltage in network cabling systems (Category 5 and Coax) and modular telephone lines. Tone Generator Features: 2-position button for single tone or dual tone signal Toggle switch to control 3 modes of operation 3-color LED indicator display for telephone line polarity, continuity and voltage testing Black and Red Aligator Clips and standard RJ-11 plug to test individual wire or RJ-11 jack Probe Features: Special inductive plastic tip, which prevents accidental shorts when using near high voltage devices Traces and identifies wires or cable in a bundle or group without damaging cable insulation Adjustable volume level for various work environments Compatible with all existing tone generators in the market Power switch to prevent battery drain