The Ernie Ball Earthwood Phosphor Bronze Light Acoustic Guitar Strings are made from 92 copper 7.7 tin and 0.3 phosphorus. Manufactured to the highest standards the Phosphor Bronze strings prevent corrosion from sweat and reduce oxidisation which produces rust. The Earthwood Phosphor Bronze are played by the likes of Paul McCartney and offer a mellow sound with warm and rich overtones. This 12 string light set has a gauge of 9-46 and produce a clear sound that works with any genre and playing style.