Martin 80/20 Bluegrass 11-38 Mandolin Strings M450's are Martin's own 80/20 bronze wound mandolin strings, which give the mandolin a rich, full toned voice. These strings are wound on state-of-the-art equipment, to Martin's specifications, using 80/20 bronze alloy wrap wire. This alloy is 80% copper and 20% zinc, which brings out a bright and sparkling tone. The result is a string you can depend on for tone, brightness and clarity on a daily basis. From C. F. Martin, a name synonymous with fine quality instruments and strings. Diameters:. .011 .014 .024 .038 inches .011 .014 .024 .028 inches Available for Order