MajorTech MT403 Voltage Tester 1000V. The MT403 is a Non-Contact AC Voltage detector with dual ranges, a low measuring range down to 12 volts and a high measuring range from 12V to 1000V. Suitable for outlets or against wire insulation testing, this non-contact AC Voltage Detector has a switch to turn the unit on and a Green LED indicates it is working. There is a Red LED and an audible sound to indicate the presence of voltage. It has a rugged double moulded IP67 waterproof housing that can withstand a 2m drop. There is a bright built-in LED flashlight ideal for use in dimly lit areas.