This is an H-string (Spirocore Medium) for a 5-string double bass. It's a used item, having been used for about a year. It's thick, so I think it can still be used, and the edges have been worn down, suppressing the characteristic glare of Spirocore strings. Spirocore H-strings, despite their thickness, respond quickly, have a clear tone, and plenty of volume. Strings have become expensive recently, so it's recommended for those who want to save money or want to try out a new string.