EJ 45 Pro-Arté Classical Nylon Normal TensionEJ45, normal tension, is D'Addario's best selling classical set, preferred for its balance of rich tone, comfortable feel and dynamic projection. Pro-Arte, the world's most popular classical strings are D'Addario's premium classical guitar string sets. EJ45 Pro-Arte treble strings are sorted by a sophisticated computer-controlled laser machine which performs diameter and tension measurements, ensuring true-sounding, precise trebles in every set. EJ45 Pro-Arte basses are wound using silver-plated copper on a multi-filament nylon core for consistent and warm, yet projecting tone.EJ45 best selling Pro-Arté set, Normal tension offers balance of volume and comfortable resistanceMade in the U.S.A. for the highest quality and performanceEJ45 String Gauges: Trebles .0280, .0322, .0403 Basses .029, .35, .043