Kong Toys provide unmatched performance and benefits. They are used and recommended by veterinarians, dog experts and satisfied customers worldwide. Kong's exclusive Ultra-Flex formulas are chewer friendly. They are unmatched for resilience, durability and bounce. Ultra-Flex rubber is nontoxic, nonabrasive, nonsplintering and does not get sharp when chewed. Recommended for Basset Hound, Boxer, Chow Chow, Collie, Dachshund, Irish Setter, Jack Russell Terrier, Standard Poodle, Samoyed, Miniature Schnauzer, Standard Schnauzer, Scottish Terrier, Springer Spaniel and other similar sized large power chewers.