The new generation of Lifespan ropes has been designed using new technology patented by Martin. This technology protects against corrosion both the core and the spinning of the string without denaturalizing the sound. Authentic Acoustic Lifespan 2.0 keep their new look longer, sound better and are more pleasant to the touch. Two years of research were needed to allow Martin Guitar to develop the most efficient long-lasting strings on the market. Available in 80/20 Bronze and 92/8 Phosphor Bronze.