It shows the fault code and generic description of fault code, you can also access the SLABs unit to read and clear codes, turn on and off some accessories, and of course monitor real time data.
The only draw back for me is that it is slightly bulky and does not like to stay connected. I often have to unplug and replug it in. This is IMO a great deal and going to tell a friend about it that bought the AB iLand product that he has never been happy with.
I should point out that you will probably need to do a software update on it the device (unless seller has already did one), not very hard but you will need a laptop or some device that accepts a USB port and is connected to internet