Gibson Phosphor Bronze Acoustic Guitar Strings 13-56Developed under the direction of Gibsons Master Luthiers, these strings are phosphor bronze wound to give your guitar a bright attack and sustained warmth, providing you with the ultimate acoustic sound. Suitable for any playing style, Gibson Phosphor Bronze strings are un coated for an authentic acoustic feel, making these a favorite for the Gibson Team in Bozeman, Montana. Features Phosphor bronze wound for ultimate clarity and warmth Developed and