brand new and high quality. Features: 1. The wiring of this voltmeter is simple. The red is connected to the positive, the black is connected to the negative, and the reverse connection is protected. 2. Conventionally do not need an external working power supply, you can work directly with the measured voltage, measuring the voltage range of the second line 2.5-30V. 3. Wide voltage operation, red minimum measurement voltage 2.5V, the maximum safe pressure can reach 40V, more than 40V may be damaged. 4. When measuring voltage below 10V, two digits are displayed after the decimal point; when measuring voltage above 10V, one digit is displayed after the decimal point. Specifications: Measuring range: two-wire for DC 2.5~30V Power supply range: no separate power supply, the measured voltage 50K Working current: