Kong Dog Toy - Original, Black For tenacious chewers. Ultra-strong black Kongs are exclusively formulated for large tenacious power chewers. Available in three sizes. Now being used worldwide by police, drug enforcement, and military K-9 teams - Schutzhund and AKC competition trainers and many more. Supervised use is strongly recommended for power chewers! Kong toys are enthusiastically used and recommended by veterinarians, trainers, dog professionals and satisfied customers worldwide. Millions and millions of dogs have confirmed that Kong is "The World’s Best Dog Toy!"