For use on cars, trucks, boats, trailers, vans, RVs, motorcycles, airplanes and snowmobiles. Use to check electrical circuits and accessories on all 6 & 12 Volt systems. Wire stretches to 12 ft for use then automatically retracts. Probe is insulated and super sharp. Heavy duty ground clip and insulator. Spring supported strain relief. Specially designed long probe accesses hard to reach circuits.