This product is for dogs, but can be used on a pet 5 lbs. and over. Sometimes we have to think outside the litter box! Our problem was we have a dog door and all of our cats would walk out the dog door and hang out all over the neighborhood. For Windy's safety, we thought about invisible fence for her. But it seemed like people had all kinds of ways a cat could get out. Then we came across this product people had used it on their cats. We set it by the back door, it the size of a smoke detector and it can only be used indoors. She wears the collar and it works! It gives a static correction to the pet that can be adjusted from 2 feet -12 feet and it can be set up for two different pets. You can also buy just a barrier transmitter and put it by your houseplants or your cat favorite scratching place that is not your favorite place at all.