For use on any grounded electrical system, DETEX Voltage Detectors are available in seven models that cover a range from distribution class to transmission line voltages up to 550 kV. Biddle offers six electronic beeper models and one model with LED indication for greater visibility when testing indoors. Designed to Rigid Safety Standards, Conforms to IEC61243-1 Contact Detection Avoids the Hazards of Extraneous Noise Pickup. A Loud Audible Tone and Easily Visible Red LEDs Indicate the Presence of Voltage, Keeping High-Voltage Workers Safe