Widely referred to as a "jazz" set Ernie Ball Extra Light Nickel Wound strings feature a wound G string. Unlike their Slinky sibling, these Nickel Wound sets are not limited to jazz musicians however. Played by The Mars Volta, Jack White, and Judas Priest, these strings are also tailor made for alternative, rock, and pop. Ernie Ball Extra Light Nickel Wound Strings are precision manufactured to the highest standards and most exacting specifications to ensure consistency, optimum performance, and long life. All wound strings are made from nickel plated steel wire wrapped around a hex shaped steel core wire. Meanwhile, the plain strings are made of specially tempered tin plated high carbon steel; producing a well balanced tone for your guitar.