Compatible with standard 12V systems plus new 42V systems found on Hybrid cars. Also checks high volt diesel injector circuits found on Ford 6.0L, 6.4L and others. Safe for low current circuits as tester only draws 3 milliamps at 12V. Automatic volt identification: Blue for 12V, Red for 42V. Features 2 bright LEDs, crystal clear handle for 360º visibility, 3 meter (10’) heavy-duty cable with hooded alligator clip and high-impact body with spring-strain relief.