Bringing together a tin-plated steel string core with a hexagonal shape wrapped in an 80% copper/20% zinc alloy, the Ernie Ball 2004 Earthwood Light 80/20 Acoustic Guitar Strings offer bright, organic acoustic tones in in an easy-to-play medium. Ranging in gauge from .011 to .052, this pack captures the warmth of the Earthwood series without the finger fatigue of heavier strings.