Ernie Ball Earthwood phosphor bronze strings provide a mellow, ringing tone with excellent clarity for acoustic guitarists. You'll love the warm, balanced sound and comfortable feel as your pick glides across the copper wire. The custom medium gauge—with sizes ranging from .012 to .056—gives you versatile, all-purpose strings for any style. Whether you play folk, rock or country, these strings help you shape a tone that's all your own.