Usage Tips:8 Function: Voltage detection, Resistance detection, Diode detection, Positive and negative pole detection, Component activation, Continuity test, Grounding test, Tracing and locating short circuits. Update with Superior Design: The P100 automotive electrical system activator is designed for 5-40V automotive power circuit diagnosis, featuring a compact and powerful design. It includes reverse connection and overload protection, ensuring safe and reliable testing. Comprehensive Features for Accurate Diagnosis: The tool probe can test conductivity, detect circuit voltage, perform positive and negative detection, and activate components, among other functions. This enables quick detection of short circuits, broken wires, or poor contacts in the vehicle's electrical system, helping users understand the vehicle's condition more accurately. Professional Use: For added safety, this automotive circuit tester includes a breaker feature that protects against short circuits and overloads. If an overload is detected, the breaker trips to safeguard both the tool and the user. The components activation function allows testing of various components such as continuity, ground connections, short circuits, and polarity detection. Two power supply modes: Power source 1: 12V or 24V, powered by the vehicle battery, Power source 2: 2 x AAA batteries(Not include). Easy Use:Clip the red lead to the positive battery terminal and the black lead to the negative. Press the (P) button will activate the probe with positive voltage. Colour:Black Material:Plastic Package Contents: 1 * Circuit Tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.