A non-contact voltage detector. Very handy for verifying whether a cable or circuit is live or dead, but not a substitute for a proper Lock-Out/Tag-Out procedure or other guidelines in NFPA 70E. Popular models include the Greenlee Volt Tick, GardnerBender Non-Contract Voltage Testers, and Fluke VoltAlert. All models have an indicator that lights in the presence of voltage, most also have an audible signal.
From Fluke Test Tools, Answering Your Electronic, Electrical, Predictive Maintenance, Calibration and Biomedical Needs
Fluke 1AC-II / 1LAC-II VoltAlert
From Fluke Test Tools, Answering Your Electronic, Electrical, Predictive Maintenance, Calibration and Biomedical Needs
Fluke 1AC-II / 1LAC-II VoltAlert