D'Addario EJ46 Pro-Arte Nylon Classical Guitar Strings, Hard Tension Hard tension for increased resistance, volume and projection Laser sorted clear nylon treble strings for consistent, precise intonation Precision wound basses for warm, projecting tone and the utmost consistency Made in the U.S.A. for the highest quality and performance String Gauges: Trebles .0285, .0327, .0410 Basses .030, .036, .044