Nickel Plated Steel, Super 250s The "high octane" nickel plated steel string for your electric guitar. With a pure steel wrap, the magnets of your pickups use the whole string, not lust the core! High energy strings transforming into high output butsts of pure sound. The nickel plating enhances feel while reducing "string squeak" and fret wear without compromising tone. Original equipment on all US made Fender guitars. Ball End Gauges: 011, 014 .018, 028w, 038w .049w