120V AC to 500 kV AC—120V AC-500kV AC detectors sense voltages as low as those in a power socket and as high as those in high-power transmission lines. Since they detect a wide range of voltages, they’re a helpful tool for rescue workers, electricians, and telecom workers. They can also connect to an app to notify emergency response services when there is a fall, injury, or no movement detected. The app is optional, and it requires a paid subscription. This safety feature makes these detectors a great option for those working alone.

2.4 kV AC to 500 kV AC—2.4kV AC to 500kV AC detectors identify a wide range of voltages found in high-power transmission lines, so they’re often used by linemen. However, they won’t detect the low voltage ranges found in telecom lines or small machinery.