GHS Bright Bronze acoustic guitar strings boast a specially tempered 80/20 copper-zinc alloy wound over a hex core to deliver an extra-bright tone. This expertly designed core-to-cover ratio gives increased brightness and flexibility. GHS strings are manufactured in a state-of-the-art, climate controlled facility using precision equipment and only the purest of materials. The air-tight Fresh Pack locks in factory freshness that endures the test of time and locks out corrosion. When you buy GHS strings, you get quality, consistency, lasting intonation and superbly harmonious sound! GHS Strings - The String Specialists since 1964.