Function Measures alternating current (AC) and direct current (DC) Converts high-current signal to low-level millivolt signal so it can be read by a testing device Hall effect clamp with 0.75" (19 mm) jaw opening measures current without touching or interrupting the circuit Zero adjust function compensates for changes in output voltage due to environmental conditions Meets applicable European Conformity (CE) directives AC/DC current clamp, 20 A Special "low current version Zero adjust knob Attached leads and users manual