Puppy Bumper - Keep Your Dog on the Safe Side of the Fence - Pastel Stripe -10"-13" Dog's own collar threads through loops to keep it in place. Light, comfortable, and machine washable. "With so many people keeping small dogs in upper-floor apartments, this is one products that really could save a life." ~ Dr Marty Becker, Good Morning America. Large-For dogs with neck sizes ranging from 10"-13".