Safety and security: The non-contact voltage tester has passed CE CAT III 1000V CAT IV 600V test certification. When the AC test pen detects the voltage, the probe will flash red and beep, the higher the detected voltage, or the closer to the voltage source, the higher the beep frequency of the dual-range voltage detector. AC Outlet Tester detects yellow flashes for low voltage and neutral triggers, and red flashes for high voltage and live triggers Non-Contact: The AC circuit tester uses a non-contact method to measure voltage, using an NCV inductive probe to detect AC voltage, simply hold the tip of the circuit tester close to an outlet or power cord to detect the presence of voltage. Dual range circuit voltage testers are safe double insulated, you don't have to worry about electrocution, voltage detection tools are very safe and perfect for helping determine neutral or live and for breakpoint testing Dual Range: The current tester detects standard voltage and low voltage ranges (12-1000V AC / 48-1000V AC), making the measurement more flexible and accurate. The NCV sensitivity is automatically adjusted from low to high. Low sensitivity can detect doorbells, thermostats, power boards, etc., high sensitivity is perfect for detection systems such as power supplies. When the voltage test passes, use a non-contact wire tester where needed. Visual and Audible Voltage Indicators Our circuit inspection testers are carefully designed with bright LED lights to help you work properly in dim environments, and AC cable voltage testers are equipped with a light spot location feature that can be used to indicate long distance lines. When the battery of the voltage detection tool is lower than 2.4V or the current detection pen does not work for 5 minutes, it will automatically shut down to save energy. Pocket-sized electric test pen with pen hook, very convenient to