Before starting the electrical installation, electricians must ensure that the working environment is de-energized. A voltage tester is needed to locate alternating electric fields or suspected fault sources. The Wiha non-contact voltage tester indicates a possible lack of voltage in advance with a light and sound signal. After switching on, a green LED light that lights up continuously indicates that it is ready for operation. When voltage is detected, the blue (weak), orange or red (strong) LED lights up, depending on the strength of the alternating electric field. The device works with two AAA batteries, which are part of the set. In order to save energy, the device automatically switches off if it is left unused for 4 minutes. The built-in LED flashlight enables the illumination of the measurement site in a dark environment and can also be used as a flashlight by turning it on and off manually. Thanks to the clip and handy size, the voltage tester fits comfortably in any shirt or trouser pocket. Thanks to the internationally harmonized measuring tip, the voltage tester can be connected to any wall outlet worldwide. The single-pole voltage tester falls under the scope of the EN 61010-1 / IEC 61326 standard and was designed according to CAT IV 1,000 VAC.