Advance Dog Potty Training BellsThe Advance Dog Potty Training Bells make training your dog to go outside without scratching, whining or barking easier. Two snaps allow for 27" or 31" lengths to accommodate most doors and sizes of dogs. Available in solid black and patterns, the potty training bells are both fashionable and functional options for teaching your dog to let you know when it needs to be let out. Hang the bells on the door handle for easy set up and let your dog tell you