ELECTRIC GUITAR STRING SET D'Addario NYXL0838 electric guitar string sets (008 - 010-015 - 021 - 030 - 038). D'Addario NYXL guitar strings stretch more, sound louder, and tune better than any string you've ever played before. Conceived, refined, and manufactured by D'Addario in New York, this freshly designed, tear-resistant, high carbon steel and smooth steel core provides a new level of freedom, confidence and power.