- These are our best-selling electric guitar strings, revered by players since 1974. - The nickel-plated steel winding provides a bright and versatile electric guitar tone, ideal for a variety of musical genres. - Like all D'Addario electric guitar strings, XL Nickel strings are made with our patented Hex-Core, ensuring perfect intonation, consistent feel, and reliable durability. - XL Nickel sets have a code on the recyclable VCI bag, which you can register to earn Players Circle points. - XL Nickel electric guitar strings are made in the USA and drawn to our exacting specifications at our New York production facility.