STRING SET FOR ELECTRIC GUITAR String Set for XL Series Electric Guitar Nickel Wound, Blues / Jazz Rock (011 - 014 - 018 -028 - 038 - 049). D'Addario XL Electric Guitar Strings have been recognized worldwide as '' The Guitarist's Choice '' among guitarists of all genres and styles. XL strings are wound with great precision with nickel plated steel onto a hexagonal shaped core, resulting in strings with a distinctive, brilliant tone and excellent intonation.