We have a yard that cannot be fenced in. I saw this on a web site and wonder if anyone has used it? I had one that we used for a dog and it work well. Our lot is a little over an acre. We are thinking about building an outdoor enclosure for the cats, but I already know that they will not like to be in it when we are out in the yard as well. Lots of loud complaints when we go out without them. Right now we put them on their leads when we go out and hook them up to various things. Are soon as we move out of range from them the complaints begin. And can they complain loud!