Product Description 80/20 Bronze are our brightest acoustic strings, made to give your guitar an unparalleled shine. These bold sounding strings were developed by John D'Addario Sr. and guitar maker John D'Angelico in the 1930s, and have been beloved for their sparkling, trebly tone ever since. Made with a high carbon steel core and 80/20 Bronze wrap wire, 80/20 acoustic strings offer remarkable depth, along with rich, bright harmonics, and powerful projection. This 12-56 Light Top/Medium Bottom Bluegrass set has powerful low-end, while maintaining flexibility for soloing. From the Manufacturer EJ14, a D'Addario 80/20 Bronze hybrid gauge, combines the medium gauge bottom strings for increased resonance and volume with light gauge top strings for more comfortable playability and single note bending. A popular choice for bluegrass pickers but suitable for many genres.80/20 Bronze, commonly referred to as brass, is the original acoustic string alloy selected by John D'Addario Sr. and John D'Angelico in the 1930s. 80/20 Bronze strings are popular for recording due to their crisp, deep and projecting tone and appeal to many traditionalists and vintage enthusiasts for their historical significance. All D'Addario acoustic strings are wound on a hexagonally shaped, high carbon steel core, resulting in long lasting, bright sounding tone with excellent intonation.D'Addario, the world's largest manufacturer of musical instrument strings, is known as The Players Choice with a reputation for unsurpassed quality and consistency. D'Addario's innovative packaging reduces waste and provides protection from corrosion. All D'Addario strings are manufactured in the U.S.A. using proprietary, digitally controlled, state-of-the-art machinery for unmatched performance, set after set.