The GHS Super Steels series is manufactured using a stainless steel wrap around the already standard stainless steel hex core. The combination delivers an incredibly bright tone and extra high volume. Mix this with some extra long sustain and you. ABOUT GHS STRINGS - GHS Strings are manufactured in a state-of-the-art, climate controlled facility using precision equipment and only the purest of materials. When you buy GHS strings you get quality, consistency, lasting intonation and superbly harmonious sound!