With voltmeter， according to a voltmeter error is + / - 0.1 V， the range is 0V to 40 V
Touch button to switch measurement input or output voltage， and indicator light show is which road voltage measuring， and keep the last set even if the power switch on again
Voltmeter can be closed， long press the switch 1 seconds or more and less than four seconds， you can close let go
With calibration function
With terminals， and the input voltage is 4V to 40V
Switchable output voltage: 1.25V - 37V
Max output current: 3A
Using internal oscillator frequency of 150 KHZ， low power consumption and high efficiency