Ernie Ball Ultra Slinky set combines the first three strings from their world famous Regular Slinky set with the last three strings from their Power Slinky set. Ernie Ball Nickel Wound Electric Guitar Strings are made from nickel plated steel wire wrapped around tin plated hex shaped steel core wire. The plain strings are made of specially tempered tin plated high carbon steel producing a well balanced tone for your guitar. .008-.038 • MFSKU P02225 • UPC 749699122258