D'Addario's heaviest gauge mandolin set, ideal for hard driving, percussive playing styles / Loopend construction for universal fit / Phosphor Bronze for long lasting, warm and bright tone / Made in the U.S.A. for the highest quality and performance / String Gauges: Plain Steel .0115/.0115, 016/.016, Phosphor Bronze Wound .026/.026, .041/.041 / Environmentally friendly, corrosion resistant packaging for strings that are always fresh