CNX-3T, extra hard tension, is a clear nylon treble classical half set optimal for maximum string resistance and projection without compromising tone. Pro-Arté, the world's most popular classical strings are D'Addario's premium classical trebles. All Pro-Arté 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. Each half set contains 3 treble strings in a convenient resealable pouch.