Thank you for visiting! The name has changed! The thread that was previously called "Tetron" is now "Polyester." The quality remains the same. This is the [Ni no Ito] (second string) for shamisen. It is mainly used for [Tsugaru-jamisen]. It's not ordinary polyester thread, but rather Raytone [radiation-irradiated thread], making it a step up in quality. The twist is similar to silk thread, offering both strength and flexibility, and is often used by [professional musicians]. This is not a used item, but rather [New], so there is no aging or deterioration. ・For multiple purchases ・For combined purchases with other items We will offer a [discount], so we would appreciate it if you could [comment in advance]. If you have any [opinions or questions], please feel free to comment on anything.