Because of their strength and durability, rope toys have always been the number one choice of tug toys. A great health benefit worth mentioning is that rope toys work like dental floss, cleaning teeth and gums while dogs are chewing on them. AKC Knotted Rope Tugs are made of 100% natural cotton rope. The big knot provides hundreds of curved surfaces for your dog to grab on to. All these little rope curves clean your dog's teeth in different directions simultaneously while your dog is chewing on the toy. AKC Knotted Rope Tugs come in two sizes: Small/Medium and Large. Small/Medium has a 3.25" knot and measures 11" long with handle. Large has a 4.5" knot and measures 15" long.