So far, this monitor has identifed several low voltage conditions in various campgrounds, has identified a pedistal that had lost its ground, and has identifed that one of the extension cords that I was using had lost its ground. All of these are potentially dangerous conditions. The display is large enough and clear enough, but quite frankly I wonder if I would have noticed that there was a serious problem without the built-in alarm that went off each time. There are lower priced monitors, but none of them have the features that this one has. It is well worth the price.