The Klein Tools CL390 True-RMS AC/DC Digital Clamp Meter, Auto-Ranging, 600V AC/DC, 400A is an automatically ranging True-RMS (TRMS) digital clamp meter that measures AC/DC current and NCVT via the clamp, AC/DC voltage, DC microamps, resistance, continuity, frequency, capacitance, and diodes via test leads, and temperature via a thermocouple probe. It features a high visibility, reverse contrast LCD display that optimizes view ability both in dark or bright ambient lighting.