1. MULTIFUNCTIONAL AUTOMOTIVE TOOL: This P50 automotive circuit tester combines 12 diagnostic functions in device check blown fuses, test battery performance, detect LAN circuits, verify Hall sensors, identify short circuits, distinguish between real electricity and poor grounding, plus features an awl function and builtin lighting for nighttime repairs. 2. REALTIME VOLTAGE DISPLAY: Equipped with a LED display showing voltage readings from 5V30V, making electrical diagnostics clear even in lowlight conditions. The rear light illuminates your work area while the display provides immediate readings during troubleshooting procedures. 3. AUTOMATIC POLARITY IDENTIFICATION: Save time with positive/negative pole recognition through intuitive LED color indicators red light signals positive connection while green light indicates negative, eliminating guesswork and reducing diagnostic time when working on complex vehicle electrical systems. 4. THREE WORKING MODES: Easily toggle between three distinct testing modes with a simple press of the button located on the tester body. Each mode optimizes the tool for different diagnostic scenarios, allowing for comprehensive electrical system analysis across various automotive applications.