Ernie Ball Earthwood phosphor bronze strings breathe life into your acoustic guitar. These medium gauge strings provide a balanced tone that complements the natural resonance of your instrument. The phosphor bronze wrap wire delivers rich bass notes and clear, articulate trebles that cut through. You'll get crisp definition and full, ringing sustain up and down the fingerboard. Built to meet the demands of world-class players, these strings hold tune even under heavy picking and bending.