DROK 0.56 inch Digital Volt Meter 600V DC High Accuracy Voltage Circuit Electrical Tester Equipment Red LED Display +/-600.0 Positive Negative Volts Measurement with Polarity Protection + / - 600.0V full measure range, 0.1V resolution. it will show "H" if over- range. It can measure po DC +5V +/-5% operating power supply with low current consumption. 0.56" red LED digital tube with bright clear voltage high accuracy reading. Selectable decimal point position, with calibration potentiometer. With polarity protection circuit, it will not be burnt if the power supply positive and negative are