EHR320's combine the universal playability of a traditional 9-42 set with the benefits of an exclusive "Half Round" manufacturing process. D'Addario Half Rounds Electric Guitar Strings are round wound with stainless steel and then precision ground leaving the outer surface smooth and "semi flat." The result is a string with the tone and tension characteristics of round wound strings, with a smoother feel, similar to flat wound strings. • D'Addario's popular extra-light gauging with an exclusive semi-flat surface • Centerless ground stainless steel delivers round wound tension with a flatwound feel • Corrosion resistant packaging for strings that are always fresh • Made in the U.S.A. for the highest quality and performance • String Gauges: Plain Steel .009, .011, .016, Stainless Steel .024, .032, .042