Originally Posted by dragon

Does it have a display? Im guessing its either an amplifer which a headset plugs into (for listening for the tones generated by the ocsillator, its easier to hear in noisy enviroments than the other type) or if its got a largish display on it its probably the tool for measusing the continuinity of the line (gives them an estimate of how far the cable goes so helps in finding discconected joints.etc)

I'd think he'll be wanting that back somehow.