Safety and security: The non-contact voltage tester has passed CAT III 1000V and CAT IV 600V safety certification. When the AC test pen detects voltage, the probe flashes red and beeps; the higher the voltage or the closer to the source, the faster the beep frequency. The AC outlet tester displays yellow flashes for low voltage and neutral conditions, and red flashes for high voltage and live circuits.Non-Contact: The AC circuit tester uses a non-contact method to detect voltage via an NCV inductive probe. Simply bring the tip close to an outlet or power cord to check for voltage presence. The dual-range voltage detector features double insulation for safety, reducing the risk of electric shock. This makes it safe and ideal for identifying live or neutral wires and for breakpoint testing.Dual Range: The tester detects two voltage ranges: 12-1000V AC and 48-1000V AC, allowing for more flexible and accurate measurements. NCV sensitivity automatically adjusts from low to high. Low sensitivity is suitable for detecting voltage in doorbells, thermostats, and power strips, while high sensitivity works well for power supply systems. Visual and audible indicators confirm voltage detection.Design: The circuit tester features bright LED lights to aid visibility in dark environments and includes a spotlight function to help trace long-distance wiring. The device automatically powers off after 5 minutes of inactivity or when battery voltage drops below 2.4V to conserve power. The compact, pocket-sized design includes a pen clip for easy carrying.Efficient: The live voltage tester is suitable for checking circuit breakers, lighting fixtures, switches, and outlets. Press and hold the red button for 2 seconds to activate. When voltage exceeds 90V, a high-voltage alarm activates and the safety symbol illuminates on screen. This NCV probe voltage detector is a reliable tool for home electrical maintenance and appliance troubleshooting.Color: Black Material: Plastic Package Contents: 1 x Voltage Test Pen Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement may vary by +/- 1-3 cm.