NIckel-plated steel on traditional roundcore;Significantly less tension, better flexibility and more sustain than hexcore strings with hexagonal core ;Optimal sound, easy to play, long sustain ;Roundcore strings must not be shortened before tensioning, otherwise the wrapping could come loose and the string becomes unusable. ;X50LM Nickel Explosion .010-.052 light-medium;Light-medium . 010 .013 .018 .030w .042w .052w;No single strings available!;