As stated, this is the 5th string (H string) for a 5-string double bass. *Please note that this item is also listed elsewhere, and purchases made there will take priority. Thank you for your understanding.* Due to the following circumstances, these strings are completely unused, having only been put on my instrument for two days by a craftsman during an adjustment. * I have attached a photo of the invoice (4th image). You can confirm the date; I received the instrument on February 9th. * Please refer to the following link for general pricing information: [https://www.kurosawaviolin.com/kurosawa_strings/strings_html/flexocor_cb.html](https://www.kurosawaviolin.com/kurosawa_strings/strings_html/flexocor_cb.html) When I sent my instrument for adjustment, I also requested a string change. However, as you know, the 5th string (which I always tune to C) is rarely played. The string itself showed no signs of wear, and the sound was still perfectly fine (and expensive...), so I only intended to have the standard 4 strings (G, D, A, E) replaced. Due to my insufficient explanation, there was a misunderstanding, and the staff purchased and installed a 5-string set, and the instrument was returned to me in that condition. (I reconfirmed, and it was installed that day, unfortunately making a return impossible.) I immediately removed the string myself upon receiving the instrument and re-replaced it with the previous strings. Therefore, these strings were only installed for two days and are essentially new and unused.