My SIL used them with her old cat, that pee'd on the couch. It was the one that would give them a shock, equivalent to a static shock. It kept the cats away, until they figured out how to maneuver around where the pad wasn't. Before that the kitten got shocked, and they found her one day smacking the power box

Now she is an adult cat, you can put the pad down and not even turn it on and she will stay away.