Ernie Ball Nickel Wound 6-String Baritone Guitar Strings are made from nickel-plated steel wrapped around a hex-shaped steel core wire. The plain strings are made of specially tempered tin plated high carbon steel. Each guitar string produces a bright, balanced tone and manufactured with small ball ends like guitar strings, not large ball ends used on traditional electric Baritone Guitar Strings. These sets are optimal for A-A or B-B tuning combinations and are a perfect match for the hybrid baritone instruments.