Designed to cope with demanding practices and schedules. Martin Authentic Acoustic SP Phosphor Bronze strings feature their highest tensile-strength core wire and are tin-plated for enhanced corrosion resistance. These Acoustic SP strings provide players with good tuning stability as well as a true and consistent tone throughout gigs. Manufactured with copper tin and phosphorous Phosphor Bronze strings yield a dark and slightly warmer tone that 80/20 strings. These Acoustic SP strings include gauge 12.5 - 16.5 - 25.5 - 33.5 - 43.5 - 55.
