🔋 DaFuRui 5Pack Green Mini Digital Voltmeter: Accurate DC 3V-30V Voltage Monitoring with 0.56 Inch LED Panel Display Review

Good value for money. As long as they work well. The amp is slightly different but adjustment is possible with the built in trimmer.

Used to show the DC voltage on the batteries that power my car audio amplifier. I would return them after three of them failed in a week. But I only started using them more than a month after delivery.

The photos show that a self-sufficient power supply and measurement up to 80 V is possible. This is not included in the blocks sent to me. The range is 0 to 30 volts, but that doesn't give me the ability to measure up to 80 volts. In other words, what was sent to me was not the product pictured.