We love our PoochieBells. We have two sets (on on the front door & one on the back door) and he picked up the idea super fast and was trained on them within the first few days! He hasn't had an accident in the house since! The other great thing is if we're in another room of the house we can always hear when he has to go. We have suggested them to many people & swear by them. We literally take them with us anywhere he goes. Thanks for making a great product & making our lives so much easier!