DISCONTINUED The DigAlert™ Probe is designed to determine, without a physical connection, if a high-frequency signal is present on a wire pair. It will directly reproduce audio signals such as speech, base-band modems, or fax tones though its primary purpose is to output a distinctive two tone alarm if high-frequency signals (such as data) are … <a href="https://www.tempocom.com/products/discontinued-identifier-digital-signal-t-bug/">Continued</a>