D'Addario EJ44TT ProArte Dynacore Classical Guitar Strings, Titanium Trebles, Extra-Hard Tension Flexible composite core for greater projection and full round tone Titanium trebles for brightness and projection Extra Hard Tension String Gauges: Trebles .0290, .0333, .0416 Basses .030, .036, .047 Made in the U.S.A. for the highest quality and performance