NON CONTACT: Voltage Tester Pen with NCV sensing probe for AC voltage; simply place the tip near a terminal, outlet, or power cord. When the nearby AC voltage is detected, the sensor head flashes red, showing more than 4 bars of signal lights and the alarm beeps quickly, and the measurement range is 12~1000V. A convenient Voltage Tester for electricians and homeowners. WIRE BREAK DETECTOR: Along the line detection, the place where there are 2 grid signal lights and the buzzer alarm is slow is the breakpoint position. IDENTIFY THE NEUTRAL LINE AND THE LIVE LINE: Use Electric Tester Pen to identify the Live Wire and Null Wire, the beep sound is slow, and the signal light flashes 1/2 grid, it is the Null Wire; the beep sound is fast, the signal light flashes more than 4 grids, it is the live Wire. ADJUSTABLE SENSITIVITY: Press the S key to adjust the sensitivity, the AC voltage detection range can be switched between high sensitivity and low sensitivity, shielding interference. The NCV sensor automatically recognizes the voltage and displays it, which is accurate, sensitive and stable. AUTOMATIC SHUTDOWN: When the Voltage Tester pen is not operated within 5 minutes and no AC voltage is detected, it will automatically shut down. Voltage Indicator features a bright LED flashlight for working in dimly lit areas; pocket sized pen hooks allow you to carry it in your shirt pocket for easy portability. Specification: Material: ABS Plastic Measuring Range: 12~1000V Alarm: Visual and Sound Powered By: 2x AAA Battery (Not Included) Size Chart: 26.3x23.7x157.5mm/1.04x0.93x6.20inch Package Includes: 1x AC Voltage Detector(4 Pack) Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful online shopping!