STRING SET FOR ELECTRIC GUITAR String Set for Electric Guitar XL Series Light Top / Heavy Bottom (010 - 013 - 017 - 030- 042 - 052). 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 core, resulting in strings with a distinctive, brilliant tone and excellent intonation.