Mini Car LED Display Digital Voltmeter DC 4-30V 0.36" 5 Digit Voltage Panel Meter Red 3 Wires

As others have mentioned, there's no provision for calibration, but I compared with several other voltmeters and it seems to be accurate.Also, the benefit of millivolt accuracy is detecting small changes, which this does well. Absolute accuracy is not so important.

I use this for my solar power on a boat. I just can't stand one decimal place voltmeters that say something like 12.8 and I have no idea if its rising or falling till it says either 12.9 or 12.7 maybe 15 minutes later.With this even if I turn on a single small LED light I can see how quickly its pulling down the voltage and more importantly if the accessory is working. If I turn on a bilge pump I can see the voltage drop immediately and know that its on. Its almost kind of like having an olm meter on the circuit too in a way.Once you use a real voltmeter with 5 decimal places like this one there is no going back !

It says this meter is "high accuracy" but in the fine print it says "Measurement precision: ± (0.3 ‰ +2 digit) " which is far from being "high accuracy". It wouldn't be so bad if there was a way to adjust the reading but on the meter I received there is none. It looks like the adjustment pot is missing.

Edit: like others have pointed out, no calibration potWorking on the K40 so far so good go for my setup... But will look for one with the cal. pot in the future

Arrived well packaged and with leaflet describing how to connect the 3 wires.Covers a wide range of voltages, but i am using it for Amateur radio to monitor the exact voltage going to a transmitter amplifier.Bright and legible.

First, these seem like a decent digital panel meter. I bought 2 and will probably buy more. I like the 5-digit display so it will show volts down to millivolts.When I received these the package had been mis-handled somewhere along the way and both units that I bought had some little plastic pieces broken off. But both of them still seemed to work OK.The accuracy was off for both meters by 0.01 to 0.02 volts, and no method of calibration was provided like the pictures showed. In fact, NONE of the pictures in the item listing matched the units that I received. The display was locked into the 00.000 mode such that there were never 4 active digits to the right of the decimal like shown.I haven't had time to test the accuracy over the full span of 0 to 30 volts yet, and may post a followup after I do that testing. For use in a variable power supply it will be good to have a steady linear reading over the full voltage range.You get what you pay for, and for the price I guess these are OK. Not fantastic, but OK. So if you need to measure DC voltage up to 30-volts these will do the job. Only 4 stars because of the inaccuracy of the pictures, broken plastic pieces, and the missing calibration adjustment.

Using this to monitor the output from my adjustable power supply which has only a 3 digit meter. Works great!

This panel meter does work, showing 1.383 V on a AA battery that my Tektronics DMM also reads as 1.383 V, which is actually pretty good. My issue is that the panel meter shows 3 decimal digits. I purchased based on the photo showing 4 decimal digits. This is not the part shown in the picture.