EJ21, D'Addario's most popular round wound "jazz" set, features a wound 3rd/G string for greater resonance and a tighter feel. Can also be used for down tuning. D'Addario is the world's largest manufacturer of strings for musical instruments. Many top guitarists won't play any other brand. Regardless of your playing style, D'Addario has a set of guitar strings that's right for you. D'Addario XL Nickel Wound Electric Guitar strings are world-renowned as "The Player's Choice" amongst players of all genres and styles. XL's are precision wound with nickelplated steel on a hex-shaped core, resulting in strings with a distinctive bright tone and excellent intonation. D'Addario's best selling electric guitar set. Round wound with nickelplated steel for distinctive bright tone. Environmentally friendly, corrosion resistant packaging for strings that are always fresh. Made in the U.S.A. for the highest quality and performance. Gauges: 12-16-24w-32-42-52.