Your Strings Matter.DAddarios XL Nickel Wound electric guitar strings are engineered to serve as the critical link between you and your guitar. XLs 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, XLs 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 CoreDAddario 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 _III_IIIOIII_IIa´center_III_IIIOIIa≪??A_ of a musical string, the 6 edge points firmly grip every turn of the wrapwire, ensuring a tight wrap and longer-lasting string.