Kumho made them for their drift team with Enjuku Racing but, while they are technically available to the general public, they are not exactly affordable. The price is so high that they are really out of reach for anyone else except their drift team. The Formula D rules state that tires used in competition must be available to the public which they technically are but since they are not realistically affordable they have been deemed illegal for competition. They still can be used for practice and exhibition just not in qualifying.