Polar = Polarities Tri= Positive - Ground - Open Onics = Electronic compatible We call it Polatron. Polatron-1 quickly and effectively troubleshoots electrical circuits From 3-60 Volt D.C on Cars, Boats, Motorcycles, Trucks and heavy equipment both polarities of the battery are needed to make a circuit complete it makes sense to use a Polatron-1 that will indicate these states by one touch of its probe. We at Auto-Tech-Tronics have designed a technique in the electrical field that can improve the art making electrical troubleshooting less complex, faster saving time and money. Anyone using the Polatron-1 and Auto tech Tronics Dynamic format will further there advance in the Electrical troubleshooting industries.