Martins next generation Lifespan 2.0 strings are engineered using a new, patented technology only available from Martin. This technology was developed to protect the core wire and the wrap wire to prevent corrosion without compromising tone the single most important attribute of the guitar strings. Authentic Acoustic Lifespan 2.0 strings look better, sound better, and feel better, providing a smooth playing experience that reduces finger drag. We invested two years developing our next generation Lifespan 2.0 strings to ensure they will sound better, longer than any other extended-life string on the market. Available in 80/20 Bronze and 92/8 Phosphor Bronze.