Martin MA550T 3-Pack Authentic Acoustic Lifespan 2.0 Treated PhBrz Medium 6-String Acoustic Guitar Set

3-Pack for cost savings
92/8 Phosphor Bronze – Medium .013 .017 .026w .035w .045w .056w   Martin’s patented Lifespan 2.0 treatment protects core and winding for strings that sound better longer. The next generation Lifespan 2.0 strings are engineered using a  patented technology only available from Martin, developed to protect the core wire and the wrap wire to prevent corrosion without compromising tone. 

See the single set here: MA550T