Ernie Ball Everlast Coated acoustic guitar strings use groundbreaking nanotechnology that repels unwanted moisture and oils that negatively impact your tone. Our proprietary treatment is applied to both the inner hex core and outer wrap wire to provide ultimate protection without compromising tone or feel. Made from 80% copper, 20% zinc wire wrapped around hex shaped brass plated steel core wire providing a crisp, ringing sound with pleasing overtones. Gauges .013, .017, .026, .034, .046, .056 Features:- •1,000 times thinner than any other string coating •Everlast treatment is applied to both the inner hex core and outer wrap wire to provide ultimate protection without compromising tone or feel •Vibrant, Expressive tone played by acoustic greats around the world •Element Shield Packaging Prolongs string life and keeps strings as fresh as the day they were made •Made from 80% copper, 20% zinc wire wrapped around hex shaped tin plated steel core wire. The most popular acoustic guitar strings provides well balanced projection with crisp pleasing highs. •.013, .017, .026, .034, .046, .056