Puppy Bumpers Ultra Solid Red - 10-13" Keep Dogs on the Safe Side of the Fence Ultra Puppy Bumpers - Made tough for active Pups! Size Large 10 -13" Neck Heavy duty, washable, cotton twill can withstand a lot of hard play! The neck loops are made of strong belting so the Ultra stays securely on your pup, yet is as easy to use as the regular Puppy Bumper. 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