Review on KAIWEETS Voltage Tester: Non-Contact And Contact Pen For 12V-300V NCV Testing, LCD Display, Live/Null Wire Detection, Buzzer Alarm, And Wire Breakpoint Finder - VT500 by David Herman

I purchased this for a specific purpose. Allows me to tell if there is current in a wire before working on outlet etc.I tested it on both 110V and also on my ipad charging cable. simply touch it to the outside of the cable and it beeps if there is current. In heavier shielded wire (power cord to compter monitor it does not register so have to test closer to the plug.If your doing electrical work, this is a must have so you do not touch/cut "hot wires"