Pursue your passion with D'Addario's most popular acoustic guitar string set, the Phosphor Bronze Acoustic Guitar Strings. Pioneered by D'Addario in 1974, phosphor strings are known for superb tone and comfortable playability. These light acoustic guitar strings help you achieve amazing performances, as they offer a warm, bright and balanced acoustic tone with excellent intonation. They have become the stage and studio choice of top guitar professionals worldwide. D'Addario leverages centuries of string-making experience to bring you the most durable, consistent and enduring guitar strings. Made in the USA for the highest quality and performance, only D'Addario strings are sealed inside and out. They feature a precision wound corrosion resistant phosphor bronze wire that is carefully drawn around a hexagonally shaped, high-carbon steel core. The result is long lasting, bright sounding tone with excellent intonation. And thanks to the environmentally , corrosion resistant packaging, the strings are always fresh. The string gauges in this acoustic string set include: Plain Steel .013, .017, Phosphor Bronze Wound .026, .035, .045, .056. The six "edges" of the core wire bite into the softer wrap wire, securing it all along its length. Since 1905, D'Addario has been providing artists and players with the tools they need to perform their magic. As musicians ourselves, we have the unique ability to engineer products that inspire other musicians. The D'Addario family's vision, creativity, passion and tradition have made us the world's largest musical instrument string manufacturer. We put our family's heart, soul and love for making music into every string and instrument accessory we create, and we never stop inspiring performance.