I have a very short raccoon fence in my back yard and I never knew if it would work. First I tested it with my volt/ohmmeter and it ruined it. I then bought one of the 8 LED testers but I couldn't see the LED from the outside in daylight and couldn't get a decent reading from it anywhere other than directly on the fence power supply. So I bought this. Thirty seconds after opening the package I had a reading and I trust that reading. Super easy, just turn it on and touch the hot wire, it will beep and read the results on the bright display. Now I'm sure my fence is working and I just threw the 8 led tester in the bin.