Master Class 80/20 Bronze strings were the first round core strings Newtone started manufacturing over thirty years ago. Their success led to the large catalog of round core strings that Newtone makes today. Round core strings are popular because of their longer life, playability and superior tonal quality, but they require a higher level of traditional, expert craftsmanship and skilled technical knowledge so they are less often made. Master Class 80/20 Bronze strings have a design unique to Newtone strings. They have a bright, acoustic sound and are available in seven 6-string sets of different gauges from .009-.042 to .013 - .056. They are also suitable for electro-acoustic guitars. Very important: Do not cut these wound strings to a desired length without first making a sharp bend into the string behind the cutting point or until the string is secured and tuned to pitch. Without either of these, the string will unravel.