D'Addario EPS540 ProSteels Light Top Heavy Bottom Gauge 10-52W offer one of the brightest and most magnetic electric guitar strings currently available. D'Addario EPS540 ProSteels Light Top Heavy Bottom feature a specialized alloy that delivers a harmonically rich, brilliant high-end, with increased crunch and sustain. Each wrap on EPS540 ProSteels come precisely wound onto a hex core using exclusive computer-controlled machines, which monitor wrap speed and tension. The result is strings with precise intonation and unparalleled consistency, set after set.