- All-in-one Power Circuit Probe Tester: tests voltage, detects positive/negative terminals, activates components, checks continuity and ground, tests trailer lights and connectors, traces and locates shorts, and provides overload protection—enabling you to quickly locate the faulty wire and its failure point. - Practical design: insulated body with a stainless steel tip for reliable polarity identification of vehicle cables and plugs. Includes a 16 ft test lead, large alligator clips, and an extended steel probe for one-handed operation. Compact and portable, essential for automotive work. - Easy to use: connect red clip to the positive battery terminal and black clip to the negative terminal. The blue digital display shows the current battery voltage, and the front light turns on. If the connections are reversed, the voltage value is not displayed but the lamp stays on. When a circuit breaker trips, the tester emits a sound prompt to alert you of a short. - Circuit breaker finder tool: 6-36V AC/DC Car Power Tester with 16 ft test lead, using high-sensitivity probes for fast and accurate detection. It saves time troubleshooting car wiring and quickly locates the faulty wire and its fault point. - Use scenarios: diagnose a dead or fluctuating battery by measuring voltage and locating shorts; verify trailer light circuits and wiring continuity before trips; trace faults in damaged harnesses during auto electrical repair.