D'Addario EXL117 Electric Guitar Strings, here in gauge 11-56, are made from Nickel Plated Steel, which provides a softer, smoother surface that's faster and easier on the fingers than stainless steel. They still retain a bright, full output. The nickel surface virtually eliminates finger noise and improves playability. This Medium Top / Extra Heavy Bottom set is optimized for down tuning to D.D'Addario uses computer controlled monitoring to ensure they have precise engineering that produces unparalleled consistency.This set has individual thicknesses of .011, .014, .019, .032, .044, .056. Great for drop tuning.