We have a beagle-ish dog that loves to run after rabbits, etc. This fence keeps her in after just a few days. She learned fast for an old (11 years) dog. We don't have to put the collar on her routinely, just now and then for a reminder. The layout was a bit of a problem. The instructions didn't make it clear that you cannot use the twisted wire in any part of the loop. We ended up having to buy more wire at Lowes to replaced the wire we messed up on.