BASS STRING SET D'Addario XL Series Round Wound Bright 12-string bass strings, Regular Light, long scale (045, .018P, .018P, .065, .025, .025, .080, .035, .035, .100, .045, .045). D'Addario XL Nickel bass strings are world renowned as '' The Bassist's Choice '' whatever style it plays. XL strings are precision wound with nickel plated steel onto a hexagonal shaped core, resulting in strings with a distinctive, brilliant tone and excellent intonation. Nickel plated steel wire wound to the core is known for its distinctive bright tone and excellent tuning for all styles.