XL Nickel Wound electric guitar strings are the standard against which all other strings are measured. XL Nickel has been revered by players everywhere since 1974. Made with a high carbon steel core and nickel-plated steel wrap wire, XL Nickel strings have a bright, versatile tone, ideal for a wide variety of musical styles. This set has the increased volume and slight additional tension of 11-49 Medium gauge strings, plus a wound 3rd string.