Ernie Ball Earthwood Rock and Blues 80/20 Bronze Acoustic Set with plain G,  .010 - .052 Wound Strings are 80% copper, 20% zinc wire wrapped around hex shaped tin plated steel core wire Plain strings are made of specially tempered tin plated high carbon steel The most popular acoustic guitar string alloy provides well balanced projection with crisp pleasing highs Element Shield Packaging Prolongs string life and keeps strings as fresh as the day they were made Made in California, U.S.A. Featuring the finest and freshest materials.