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. 13-56 Medium gauge strings provides maximum volume and projection, with more tension and resistance.