Lisle Heavy Duty Circuit Tester - 32900 is a professional-grade tool designed to help diagnose electrical problems in 6V and 12V systems. It features a bright LED indicator, heavy-duty insulated probes, and a long 10 foot cord for easy access to hard-to-reach areas. It can be used to check for shorts, grounds, and open circuits, and it has a built-in LED flashlight for working in dark areas.