ECG25, one of D'Addario's best selling flatwound sets, delivers a smooth feel, warm/mellow tone and tighter tension, ideal for traditional jazz playing. 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. Popular flatwounds with smooth feel, warm/mellow tone and tighter tension 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 .012, .016, Nickel Wound .024, .032, .042, .052