I'll be honest, I was really hoping for a poor man's circuit analyzer (which run ≈$300) when I purchased this. That is definitely not what this is. Like a standard outlet tester, this will only display one type of fault at a time. So if an outlet is ungrounded, it will not also indicate reverse polarity or any other issue. I have also found it falsely detects a ground more often that Klein's standard outlet testers (RT110 and RT210). I only still use it because the attached cord spare me from having to crawl into tight spaces occasionally. A small extension on a regular outlet tester would accomplish the same thing.