XS Nickel coated electric guitar strings provide the longest life of any D’Addario electric guitar string. Coated with a groundbreaking XS coating, these premium electric strings attain maximum life and a smooth, fast feel without dampening their outstanding tone. Constructed with a NY steel core, reformulated nickel-plated steel wrap wire and Fusion Twist technology, XS nickel strings boast superior strength and tuning stability, plus richer harmonics, greater clarity and remarkable definition with every sweep, slide and bend.