Features： 1、Voltage Meter: The digital voltmeter has a wide testing range of 0-100V, which also has high accuracy and reliability. 2、Clear Display: 0.56in large digital display enables a clear view for the voltage, making the operation much easier. 3、The Work Tips: This voltmeter needs 5-30V external power supply, and the stable working has high safety and efficiency. 4、Simple Wiring: The black wire is the common negative pole, the white wire is connected to the positive pole of the measurement voltage, and the red wire is connected to the positive pole of the working power supply. 5、Easy to Install: Compact in size and light in weight, the installation is very simple to be completed within minutes. Specification： Item Type: Digital Voltmeter Material: Plastic Size: Approx. 48 x 29 x 22mm / 1.89 x 1.14 x 0.87in Package List： 1 x Digital Voltmeter