Review on Caldwell's Pet Supply Co. Dog Doorbell Potty Training Bells for Efficient Dog Training, Housebreaking, and Potty Training Your Puppy or Dog – Loud Dog Door Bell by Lisa Zimmerman

We had several dogs and they were always indoors, outdoors. This means they must be potty trained. Our newest addition, a 4 month old German Shepherd, couldn't even think about going outside. He knew he wasn't allowed to go in and knew he enjoyed going outside, but he didn't know how to let us know when he needed to get out. Trains sometimes respond to doorbells and the like. After receiving the goods, we hung them on the door, we usually go to the pot, and he realized that he had to call to go out within a day. That was a few weeks ago and the house hasn't had an accident since. He comes up and uses his snout to ring the bell, then sits down and waits for release each time. Went like clockwork!