"I bought this so my Totty would stay in the back yard. I also spent an extra $150.00 to have it installed. My rotty was outside when a cat came through the yard and then as he chased it it was as if there was no invisible fence and he ran right past it. Then he couldn't get back, so I had to gpo get him and bring him back. I had to remove the collar first so it would not shock him on the way. What good is this if the pet can get out. Wasted money as I said."