Product Information: D’Addario banjo strings are trusted by legends like Ralph Stanley, Rob McCoury, Ron Block, Alison Brown, and more, for their authentic tone and reliable performance. They are made from the highest quality plain steel, stainless steel, nickel plated steel and phosphor bronze and available in a wide variety of gauges. Product Features: Phosphor Bronze wound 4th string for added warmth Loopend construction for universal fit Preferred for its warm, bright, and well balanced tone Made in the U.S.A. for the highest quality and performance String Gauges: Plain Steel .010, .013, .016, Phosphor Bronze Wound .023, Plain Steel .010 For more information and specifications, please refer to the manufacturer’s website