Evelots Dog Doorbell for Housebreaking, Housetraining, Puppy Potty Training This dog doorbell trainer is a simple and powerful tool for your dog to help with potty training. By simply attaching the doorbell to the bordering area of your door, your dog can grab your attention by ringing the bell with his or her nose, paws, or tail! This will also help to prevent your dog from scratching at the door. Great for training puppies or even older dogs entering into a new home. Installation is as simple as screwing in the nails through the two holes on the bell base where you would like the bell to ring. Be sure to place where dog can easily reach depending on the size. The bell has a nice traveling ring so that it can be heard in other rooms to effectively grab your attention. Comes with one bell ringer and 3 screws as well as 3 sheet rock screws. Measurements: The top to the bell measures 3.5" and the bottom to the top is 4.5". The bell sticks out about 2.25" from the wall. Evelots has more than 500 products to offer. Please don't forget to visit our Amazon store.