- Non-contact AC voltage detection: NCV inductive probe lets you check for voltage without touching conductors. Simply place the tip near a terminal strip, outlet, or supply cord. If voltage is present, the tip glows red and the pen beeps. The device can automatically identify live or neutral wires, making breakpoint tests easier for electricians and homeowners. - Dual range for flexibility: Detects standard and low voltage (12-1000V AC / 48-1000V AC). Use the S button to adjust sensitivity and switch to the low voltage range for doorbells, thermostats, irrigation wiring, and other low-voltage applications. The NCV sensor automatically recognizes voltage and displays it on a bar graph. - Clear alarms and indicators: Provides multiple alerts through sound and light. When voltage is detected, the tip emits a red light and a beep. The audible alert frequency increases as the sensed voltage is higher or the tester is closer to the source. The display changes color: red for high voltage and live wire detected, green for low voltage and no live wire detected.