The basses of this set are plated with pure 24K gold, and are designed to resist the effects of acid perspiration, making them ideal for those with sweaty hands. Unlike other brands whose "gold" strings are made of less expensive alloys, these strings are quite impervious to acid corrosion. In keeping with their premium nature, the ends of the bass strings have a softening wrap designed to buffer the string where it attaches to the bridge. (The trebles are the same as in the 815 series).