Everly Sessions Acoustic Guitar Strings - Phosphor Bronze - HVY - 13-56 - 1 Pack Heavy Gauges: .013, .014, .024w, .030w, .038w, .056w Unparalleled response and continuity, smooth and balanced for studio work. Phosphor bronze alloy construction enhances sustain and durability. These strings were coiled by employees wearing surgical gloves to ensure that yours are the first human hands to touch them.