The Martin Guitars MA175T Acoustic Lifespan 2.0 strings for acoustic guitar have been developed with a new and patented technology. Both the winding and the string core are coated without affecting the sound. The MA175T Acoustic Strings have an extended life span with optimal sound and constant quality. They are made of 80/20 bronze. The corrosion-resistant acoustic guitar strings offer good playability and a pleasant playing feel. Due to the own string production the strings are optimally tuned to the Martin guitars.