Easy to Use: Built-in flashlight for convenient testing, our automotive wire tracer provides clear visibility in dark or dim areas. Compact and portable design fits easily in your car trunk, making it convenient for on-the-go use Long-Distance Usage: Our probe tester comes with a 19.7 ft cable. It includes universal connectors for most devices, supports testing polarity, current, resistance, frequency, continuity, duty cycle, fuel injection, diode check, and component activation Injector Testing: The power circuit probe can check fuel injectors, monitor frequency and duty cycle, and analyze the fuel delivery process to ensure each injector fires correctly. Quickly identify injector faults for accurate diagnostics Professional Diagnostic Tool: This power circuit probe tester has a 1.77 in TFT color screen for real-time waveform and numeric readings, featuring 7 buttons for testing DC/AC voltage, frequency, duty cycle, fuel injection, resistance, and diode check Wide Voltage Range Detection: The automotive circuit tester supports range detection from -110V to +110V DC, meeting testing needs for new energy, fuel vehicles, and high or low voltage systems in trucks (Not suitable for household 220V circuits)