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. 9.5-44 Super Light Plus strings are a good middle ground between 9s and 10s, and are good for balancing tension between varying scale length guitars.