BASS STRING SET XL Series Round Wound Bright bass strings, Super Light, long scale (040 - 060 - 075 - 095). D'Addario XL Nickel bass strings are world renowned as '' The Bassist's Choice '' whatever style it plays. XL strings are wound with great precision with nickel plated steel on 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 fine tuning for all styles.