It's great when a tool is perfectly designed and does what it's supposed to do. This tester conforms to this standard. It's easy to read (in fact, the reading automatically brightens as the sunlight brightens), no ground wire is required (the tester simply touches a hot wire with the probe), and its shape easily fits a pocket or tool. bag/belt. I once ordered a tester when I thought my electric fence wasn't working but before it arrived I found a gate had been left open. I was planning to return the tester as soon as it arrived as I no longer need it, but it is so well designed that I will keep it should I have any problems with the fence in the future. This is a great device.