Ernie Ball Earthwood Phosphor Bronze Acoustic Guitar Strings in Medium 13-56 gauge deliver rich, balanced tone and lasting durability. Crafted with phosphor bronze, these strings offer warm, bright sound ideal for a variety of playing styles. Their medium gauge provides a perfect blend of playability and projection, enhancing your acoustic performance with clear, vibrant notes. Upgrade your guitar’s voice and enjoy reliable tuning stability with these premium strings.