It has a few functionalities: 1) It’s a Step Down/Up Power Supply, 2) It’s a Voltmeter, 3) It’s an Ammeter, 4) it’s a USB powered thermometer.
It’s well made and compact. Buttons are not impressive but are functional and work well enough. It feels nice and robust.
Using it was a bit tricky at first, but once you memorize a couple of things it’s easy to use. Pressing and holding the on/off button for 10 seconds switches between two modes: Power Supply (they call it PER) or Multimeter (they call it VAH).
As a Power Supply, only the voltage can be set, however it can be turned on or off, and you get to see the current load. In this mode, it provides over current protection, and I tested it by shorting the outputs. It displayed an error, which was impressive for a product like this.
As a Multimeter, it’s easy to set up, and is accurate enough for simple projects. I especially liked that it’s really simple to use it to measure current load of projects. One thing to keep in mind is that when using it as a Multimeter, it has to be powered up by a source (through its USB-A male, USB-C female, or Micro USB female ports).