Bringing together features like 80% copper/20% tin alloy composition wire wrapped around six-sided tin-plated steel wire, the Ernie Ball 2002 Earthwood Medium 80/20 Bronze Acoustic Strings elicit some of the most faithful tones from your wooded instrument. Built on a gauge size from .013 to .056, the bright, crisp tonality inherent in these strings perfectly complements your natural acoustic tone.