Klein Tools CL390 is an automatically ranging true root mean squared (TRMS) digital clamp meter. It 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.