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.