This set of thin sheep wool Tekhelet Strings follows the Radzyner Hassidic Tradition and includes four dark blue strings that are to be used with white strings for fulfilling the commandment to wear Tekhelet strings. This set of Tzitzit Strings can be used with a Tallit Katan or Tallit Gadol and gets its color from a squid or cuttlefish. This set of Tzitzit strings does not include white strings that are used together with Tekhelet. The dye on these Tzitzit can fade over time and will rub off over time. This is normal and does not mark the strings as defective.