Kong's Extreme Black 'Power Chewer' Toys are ideal for large, aggressive chewers. Made from Kong's exclusive black natural rubber formula which is the 'World's Strongest Dog Toy Rubber'. Puncture resistant and used by power chewers worldwide. Provides mental stimulation, satisfies chewing needs, cleans the teeth and massages the gums. You can also place a treat inside the Kong for extra stimulation. Available in two sizes: Large (for dogs 15-30kg), XL(dogs 25-40kg) and King (35kg+).