1.Non-Contact Testing - Intelligently identify live/null wires and breaks by simply holding the tip of a non- voltage tester close to a patch panel, receptacle or power strip. The higher the voltage sensed or the closer it is to the voltage source, the higher frequency it beeps.The UT12E has a vibration function and the UT12M has a flux sensing function. 2.Sound and light alarm function :When voltage is detected, the tip of the tester emits a red light and a buzzing sound. When zero wire is detected, the LED screen turns green and there is no sound/slow beep; when fire wire is detected, the screen turns red and a fast beep sounds. 3.Multi-function design :The indicator pen is IP67 dustproof/waterproof design and can withstand a drop of 2 metres. Compact size, can be easily put into clothing pocket, easy to carry. Low voltage indicator, will automatically switch off after 5 minutes of inactivity. The product comes with a torch, which is convenient for working in dim environments. 4.Auto shut-off feature: If there is no operation for 3 minutes and the pen does not detect AC voltage, the pen will automatically shut off. The package comes with a non- stylus, a manual and two 1.5V AAA batteries.