Long-lasting Light guitar strings ideal for acoustic and fingerpicking.XT Acoustic Phosphor Bronze Guitar Strings from D’Addario are designed to preserve the natural tone and feel of uncoated strings. This set of Light strings are ideal for all genres, especially acoustic and fingerpicking. D’Addario XT Acoustic strings feature high carbon steel cores with an extended lifespan treatment on every string in the set, providing enhanced break resistance, pitch stability and performance.