D'Addario EJ15 are extra light strings for acoustic guitars with a warm and bright tone. I purchased them about 10 years ago and they are unused. They haven't been opened, so they haven't rusted. - Brand: D'Addario - Model: EJ15 - Type: Phosphor Bronze - Gauge: Extra Light .010-.047 - String Diameters: .010, .014, .023, .030, .039, .047 - String Color Code: Purple, Green, Black, Red, Copper - QR Code: Yes Thank you for looking.