This product appears to be based on the open source parts of the Nordic Semiconductor PPK2 power analyzer. The software is nearly identical to the PPK2's app but the hardware is capable of 6A output instead of the 1A supported by the PPK2 and it lacks a connection to allow it to be used as a current meter alone. It also doesn't exhibit the current noise the PPK2 has when driving highly capacitive loads. This is a great tool for estimating the battery usage of electronic devices that have highly variable power needs. For example, an IoT device might spend 99.9% of the time in a mode that takes very little power and .1% of the time in a second mode communicating with an access point using much more power, but the energy consumption associated with each mode may be similar. By rapidly switching between multiple current measurement ranges, this can calculate an average current consumption of this type of activity with enough precision to make the overall measurement accurately.Although the unit is well made and packaged, it only comes with a single page, unintelligible, instruction sheet that points you to a file sharing site where the software can be downloaded. The software, on Windows, requires a version of the Microsoft VC Library to be installed on the computer. If you don't already have that installed, a version of it is provided in the downloaded .zip file. The application itself is provided as a .zip file in the download that you extract to a folder. The application is "bluebird.exe" in the extracted folder. The application is very basic and allows you to set the output voltage, enable or disable the output, and record the current waveform for a selected period, at a selected sample rate. The interface implies that the samples are stored in RAM. A section of the waveform can be selected and the software will calculate the section's statistics. There are six sample rates from 1 sample per second up to 100000 samples per second with a factor of 10 between each allowed rate. At the lowest current range, the resolution is 43.68nA. The output voltage of my unit is well within 1% of the programmed value. The current measurement was off by 2% at the highest current range but within 1% in the lower ranges. This meter can't measure negative currents and its output doesn't sink current actively to maintain the output voltage when the load attempts to drive current into it, so the output voltage will rise and exceed the setpoint. My unit has a voltage dependent, no load, measurement error from 35nA at 0V to 70nA at 5V. The output is not isolated from the USB port; the negative output terminal appears to be connected to the ground pin of the USB cable. With the exception of the documentation, this is a very nice product and I recommend it if its output range of .5V -5V and 6A fits your needs.