This is a 3-strand Tetoron thread material used for folk songs. 12-3 Unopened. Please understand that this has been stored at home. Made by Marusan Hashimoto, which has been making shamisen and koto strings with traditional techniques since its founding in 1908. This is a hard-to-break synthetic fiber thread, and because it is also cheaper than silk thread, it is used for practice in place of silk thread. As a characteristic of Tetoron thread, it feels a little harder than silk thread, and the sound tends to be muffled. The hardness of the thread is also suitable for hot weather such as summer, places with strong stage lighting, and dry overseas environments.