That is the system I used. The only negative thing that I did not like was that it is circular. I only wanted to contain in the backyard, so it was impossible to set the boundary the way I had wanted. It did work for me because I have a hedge around my backyard, (not allowed any fencing due to homeowners association rules >

), so in the 2 week training with the flags, I placed them all in front of my hedge and I brought Maddie to where I knew she would get a correction if she crossed the flag for training purposes. She had one correction, and she has never needed another one. She quickly associated the flags with the boundary, so she pretty much stays inside the hedge now. She only wore the collar for about 3 months whenever I took her outside. She is completely collarless now.

Of course, she was and is never unsupervised outside either, so she pretty much just hangs around the backyard with us.
I have to tell you, this is not something that you can just set up the transmitter, put the collar on, and let the dog go. There is very intensive training that goes along with this system. The dog needs to learn the boundary.
I do like this system because it has 4 levels of correction. Yes, I have tried it before I even put it on my dog. I got to level 3 and was too chicken to try level 4. Level one, which is all that I needed for Maddie, is just a feeling of "what the heck was that?" It just gets your attention. Level 2 was a more rude awakening of kind of getting a quick shock. Level 3 felt like a shock you would get from an electrical outlet, and level 4 I did not try. :? I only needed level one once. It also has a beep only mode. Before the dog gets the shock, the collar will start beeping, if the dog does not retreat from the boundary, then it will shock. When the dog is fully trained and understands that beep sound, you can put the collar in beep only mode and it will not shock.
I know a lot of people do not like these systems. I don't really recommend them unless I know the people are going to work and really train the dogs with the system. I only used it because I worked with a trainer that came to my house to work with Maddie and myself on recall and basic obiedience. After a month and $1000 later, she was no better about running away and chasing everything that walked along the sidewalk past my house. I used this against my trainers advice, and it worked. He still does not recommend them, but he was a bit "shocked" (no pun intended :lol: ) at Maddie's complete turn around with her training after using this system. He has seen and has worked with dogs that have been "ruined" by these systems. He warned me before I used this system that they can cause severe behavioral issues. I know and have talked to 6 neighbors in my sub division that use the invisible fence, and all of them only have good things to say about it. I'm sure a few people on here will chime in with negative things to say about these things, which is fine, you should have some pros and cons to help you with a decision. Consider this one a pro! :wink: