Made from 80% copper, 20% zinc wire wrapped around hex shaped brass plated steel core wire. The most popular acoustic guitar strings provide a crisp, ringing sound with pleasing overtones. Gauges .011, .015, .022w, .030, .042, .052 Ernie Ball 2004 Earthwood 80/20 Bronze Light Acoustic Guitar Strings 1152 Features at a Glance: Type: Acoustic 6-String .011, .015, .022, .030, .042, .052 Bright tone Tin-plated hex steel core 80/20 bronze wrap Ernie Ball Earthwood 80-20 Bronze strings give you a bright and shimmering tone! [https://www.recomusic.com.my/image/recomusic/image/data/all_product_images/product-3056/P02004.png]