Martin?ÇÖs 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 ?Çô 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.Martin has invested two years developing the next generation Lifespan 2.0 strings to ensure they will sound better, longer than any other extended-life string on the market.String Gauge 13-17-26-35-45-56Tension 190.2Martin Strings Item No. 41Y18MA550TGet yours today; with the security of our many decades of experience and Sam Ash Music?ÇÖs efficient order processing, your satisfaction is guaranteed!