The 77 series Tone Generators have become an industry standard component in the tool kits of technicians in all of the premise and outside plant wiring industries. By applying a tone signal to a wire pair or single conductor, and using a probe, the tone generator permits tech's to identify the conductor within a bundle, at a cross-connect point or at the remote end. These tonr generators can be used on twisted pair wiring, single conductors, coaxial cables, de-energized AC wiring and most other wiring.