Review on 📊 bayite Pack of 5 Three-Wire Calibratable DC Mini Voltmeter: Monitor Car/Motorcycle Battery Voltage with 0-30V Range, Mountable Tester Gauge, 0.36" Blue LED Panel Display by Shawn Reiter

I hooked it up to read from zero to just over 5 volts and all five read the same. That tells me they're pretty good! Very bright (adjustable) and responsive. I have bought several of these kits. Caution: The wires are very small and brittle, almost impossible to strip, and are attached to an equally microscopic end of the wire with a microscopic amount of solder. Be careful with this! (Yes, I successfully connected the wires, but trust me, you don't want that!) As long as you're careful not to stress the connections, you'll be fine.