Since D'Addario introduced Phosphor Bronze strings in 1974, they've been synonymous with warm, well-balanced tone. XT Phosphor Bronze resophonic guitar strings offer that and more, boasting enhanced break resistance, better pitch stability, and longer life than standard resophonic strings. The XT coating delivers advanced corrosion resistance, while still retaining the warm tone and natural feel of the uncoated string. Beneath the coating, these XT resonator guitar strings are constructed with a NY Steel core, phosphor bronze wrap wire, and Fusion Twist technology, affording tonal versatility with added resilience. This 16-56 Medium gauge resophonic set is optimized for resonator guitars.