Just installed today. Works great if you already have a fence to slow them down. This will surely prevent them from digging under the fence. But in open areas with no obstacles, they'll eventually learn they can run right through. I left the gate open to see if my Ted would go through. It took him 10min to discover if he runs through, he won't get shocked.I was initially concerned about the contacts on the collar being uncomfortable for Ted because they look like two spikes poking at his throat, but he didn't try to shake it off, gag or seem uncomfortable at all. After a couple of hours, I took the collar off to install his dog tag. When I put the collar back on, he didn't try to fight it. You obviously don't want to tighten it too much. I still wish there was a better way to do this without those metal posts.The installation and initial settings are not intuitive, but I'm hoping now that I have it set up I won't have to go through the process again. I almost shouldn't have read the instructions because they left me more confused. The instructions are very wordy for just for the sake of being wordy. There are all kinds of proprietary terms. There's a glossary of some terms, but it doesn't contain the terms that will confuse you. If you're confused by this, it's exactly how I felt when I read those instructions. For example, setting the intensity of shock (which they call "correction")... You'd think with only 1 button on the collar, it would be easier to set this but you press, wait for light, within 5 sec, press again, wait for lights to flash, count the flashes. Press again an unknown number of times.... I still don't get it. But I managed to set it on the level I wanted and I hope it stays there. As for wiring it up, I thought I had it figured out by just by looking at the contacts on the transformer and the control unit. Then I thought I had it wrong after I read the confusing instructions five times. So I said to heck with the instructions, hooked it up my way and I guess it turned out to be the right way.Anywho, it works in my application. Setup was dumb, but that's done. Now I can stop hunting down my dog.