Gauge: .46.Pro-Arte Classical Guitar strings are D'Addario's premium classical guitar strings. Treble strings are measured by a sophisticated computer-controlled laser which performs consistency and quality checks, insuring true-sounding strings in every set. Basses are made with 80/20 bronze wound on nylon.D'Addario is the world's largest manufacturer of strings for musical instruments. Many top guitarists won't play any other brand. Regardless of playing style, D'Addario has a set that's right for .