ECG24, D'Addario's best selling gauge of flatwound strings, delivers a balance of smooth feel, warm/mellow tone and optimal tension, ideal for traditional jazz, rockabilly twang, R&B and some pop/rock styles. D'Addario Chromes are wound with flattened stainless steel ribbon wire which is polished to an incredibly smooth surface. Chromes deliver a distinctive damped but tone-rich sound that only flatwounds can produce. D'Addario Chromes are the world's most popular flatwound strings. D'Addario's best selling flatwounds offers balance of smooth feel and warm, mellow tone Ribbon wound and polished for ultra-smooth feel and warm, mellow tone Environmentally friendly, 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 .011, .015, Nickel Wound .022, .030, .040, .050