Automotive Test Pen - Car/Truck circuit tester with a long probe to reach hard-to-reach areas; displays positive and negative poles; convenient to use. Circuit Tester for Car - Simple, practical design for automotive use; easy to operate and versatile in testing car circuits; also labeled Bulb Repair Test Pen. Light Tester - Built with break-resistance capability and practical design; excellent texture; a reliable car automotive circuit tester for checking lighting circuits and related wiring. Voltage Test Pencil - Quickly and easily identifies faults in automotive circuits; an essential tool for mechanics or DIY enthusiasts; fits car circuit testing tasks. Use scenarios - In the engine bay, reach tight spots with the long probe to verify circuit power and ground connections without disassembly. - Check headlight, turn-signal, or fuse circuits by confirming polarity and continuity in a simple plug-and-test workflow. - On-site fault identification for non-start or intermittent electrical issues, rapidly pinpointing suspected wiring or connector problems.