Strings for electric guitar. EPN120's combine the playability of D'Addario's popular super light set with a warmer, vintage tone. D'Addario XL Pure Nickel strings look back to the '50s, when nickel was the primary alloy found in electric guitar strings. Pure nickel strings would be supplanted by nickelplated steel in the '60s when guitarists required brighter tone and enhanced magnetism. Pure Nickel brings back the richer, warmer timbres found in traditional blues, classic rock, rockabilly, and more. Super Light gauge. Gauges: . 009, . 011, . 016, . 023, . 031, . 041