DAddario J51s feature polished basses for reduced finger noise, making them ideal for recording. These hard tension strings are a popular choice for their rich tone, increased resistance, and strong projection. Pro-Arte, the worlds most popular classical strings are DAddarios premium classical guitar string sets. All 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. Pro-Arte basses are wound using silver-plated copper on a multi-filament nylon core for consistent and warm, yet projecting tone.DAddario, the worlds largest manufacturer of musical instrument strings, is known as The Players Choice with a reputation for unsurpassed quality and consistency. DAddarios innovative, environmentally friendly packaging reduces waste and provides protection from corrosion. All DAddario strings are manufactured in the U.S.A. using proprietary, digitally controlled, state-of-the-art machinery for unmatched performance, set after set.