Elixir .130 single string for a guitar. Please note that this is not a set. There is no packaging box. The exact date is unknown, but it was likely obtained over 15 years ago and has remained unused since then. The paper bag is marked 13432CSENV, but the part number didn't come up in a search, so it may have been discontinued. The paper bag is quite discolored, and although unused, it is old and may have some rust and dirt, so please be aware of this.