BK Precision 391A Manual-Ranging, True RMS Digital Multimeter with Logic Test, 20 Amp, 750VAC, 1000VDC, 20 Megaohms, 200 kHz Digital multimeter measures current, voltage, resistance, and frequency True RMS (root mean square) meter provides accurate readings when measuring linear or nonlinear loads where the current or voltage has an undistorted or distorted waveform Logic test reports the logic state of an electronic circuit Audible continuity sensor confirms a circuit conducts electricity, and diode test detects proper functioning of a circuits diodes Meets International Electrotechnical Commission (IEC) safety standard 61010 and is certified for Category III installations up to 1,000V