Your Strings Matter.D'Addario's XL Nickel Wound electric guitar strings are engineered to serve as the critical link between you and your guitar. XL's are precision wound with highly magnetic nickel-plated steel to exacting specifications, resulting in strings with long lasting, distinctive bright tone, and excellent intonation. Ideal for the widest variety of guitars and musical styles, XL's are the choice of countless professionals around the world.Round WoundThe most popular and universal construction, Round Wound strings deliver the traditional textured feel most players are familiar and comfortable with.Nickel-plated SteelRenowned for their distinctive, bright tone, XL nickel-plated steel is the industry standard for many genres and playing styles.Hex CoreD'Addario Nickel Wound strings are wound with nickelplated steel onto a carefully drawn, hexagonally shaped, high carbon steel core. A high carbon steel alloy that is six-sided in cross section. When usedas the core or â??centerâ? of a musical string, the 6 edge points firmly grip every turn of the wrapwire, ensuring a tight wrap and longer-lasting string.The D'Addario DifferenceIt all starts with our exclusively engineered and built string winding machines. There is literally nothing like a D'Addario string machine. The combination of the most advanced computer-controlled winding technology and stringent incoming wire inspection delivers unmatched consistency, string after string, set after set. Every D'Addario string is made in the USA, ensuring the highest quality and performance.String alloys have a dramatic impact on your tone, feel and string life. D'Addario's diverse selection of electric string alloys include:ViewNickel WoundViewChromesViewPure NickelViewHalf RoundViewPro SteelMellow??Bright???Super Bright?Round Wound???Flat Round?Half Round?