EXPAWLORER Set of 2 Dog Doorbells, Housetraining Bells for Potty Training One set include 2 pcs training bell, One is paw and pet print ribbon design, one is mustache designer print ribbon. With 4 bells and 1 bone charm Super strong, chew resistant nylon tested by our very own pooch. The bell is copper material and voice loudly. Quickly and easily train nearly any puppy, doggy or grown dog to let you know when he or she needs to go Proven as an effective method for housebreaking, housetraining, potty training for your doggy Compared with others, our training bell has a bone tag which can be engrave your pets name.