Senses voltages without contacting the source electrically. Telco Sales Foreign Voltage Detector (FVD) tests for potentially hazardous AC voltage that may be encountered by technicians in the low voltage and communication industries. The FVD warns technicians of hazardous voltage without contacting the electric source. The FVD provides visual indication of the amount of AC being detected on a 10 step bar graph. An audible alarm will sound if the detected AC voltage exceeds 50 volts