Review on ⚡️ Mini Digital DC Voltmeter: Waterproof, Dustproof, Drop Resistant Tester - 3 Colours (Red, Green, Yellow) by Larry Morris

Great! they are small, light and very accurate. I compared their readings with my digital voltmeter and they agreed to within a hundredth of a volt. This started with a single cell 3.7V battery plus four cells to see if the readings were accurate over the full range of the device. Exactly. The set contains 5 pieces in different colors. I love them, I will use them on my racing quads, my microcontroller projects, my solar energy projects, everything! I hooked one up to a standard XT60 connector for an extra little field battery voltage check too!