Specifications
Voltage Measuring Range: 3V to 100V DC
Operating Voltage (VDC): 4.5 ~ 30
Current Consumption (mA): ≤40
Display ON Voltage (V): 3
Display LED Color: Red
Accuracy: 0.1V
Wires: 3
Cable Length (cm): 13
Refresh Speed (ms): 200 (one time)
Operating Temperature (°C): -10 to 60
Height (mm): 22
Length (mm): 48
Width (mm): 29
Weight (gm): 15.4

Features
Very small and lightweight voltmeter module.
Very handy and easy to use.
Red LED display.
Best operates in the working voltage range of 5V to 24V
Recommended device Operating Voltage: 5V DC
Matt finish Display glass makes display Digits more Lucid in the daytime.
100% Brand new and high quality.

Description
This is All new tiny and compact digital voltmeter with a red LED Display.
The Red wire is to connect to the positive pole, the black wire is to connect to negative pole and the yellow/white wire is to connect to the positive pole of that source or another source across which we meant to measure the voltage.
While measuring the supply voltage of another source make sure that the negative pole is joined common.
To reach the best measurement accuracy, this voltmeter will automatically move the decimal point’s position according to the different measuring voltage.
When it measures the voltage below 10V, it will display two places after the decimal point.
When it measures the voltage above 10V, it will display one place after the decimal point.
This voltmeter can be used to measure the storage battery’s voltage up to 100Volts in motorcycles and cars and also can grasp the storage battery’s status.
It also can be used to measure other DC voltage.
This voltmeter can operate on versatile 4.5V to 30VDC range is the voltmeter’s maximum operating limited voltage, please leave enough margin (i.e. do not reach up to last limit which is 30V ) when working, to avoid voltmeter’s permanent damage because of an electrical spark, power supply ripple, or other too high abrupt change of voltage.

Note
Consider 1V voltage drop at voltmeter itself, as we observed it at while testing this Voltmeter.
Connections
Red Wire: Positive of the Power supply
Black Wire: Negative of the Power supply and also used as the negative of the measurement voltage source
Yellow/White/Blue: Positive of the measurement voltage source.
The display on Voltage: 3 V.(but not measure accurately up to 3.6V).