D'Addario's most popular acoustic set, EJ16 delivers the ideal balance; volume, projection and comfortable playability; D'Addario's most popular acoustic guitar string set, known for its superb, long-lasting tone and comfortable playability Preferred for its warm, bright, and well balanced acoustic 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, Phosphor Bronze Wound .024, .032, .042, .053; Phosphor Bronze was introduced; string making; D'Addario; 1974 and has become synonymous with warm, bright, and well balanced acoustic tone. D'Addario Phosphor Bronze strings are precision wound with corrosion resistant phosphor bronze onto; carefully drawn, hexagonally shaped, high carbon steel core. The result; long lasting, bright sounding tone with excellent intonation.