NYXLs feature D'addario's exclusive New York manufactured, high carbon steel alloy for unprecedented strength – Play Fearlessly. Improved tuning stability compared to traditional nickel wound strings - get in tune faster, stay in tune better. NYXL1152 offers moderate flexibility with booming, tight low end: Plain Steel .011, .014, .018, Nickel Wound .030, .042, .052. Environmentally friendly, corrosion resistant packaging for strings that are always fresh