Nickname of legendary Panamanian boxer Roberto Duran. In spanish, it translates to "Manos de Piedra". Generally recognized as one of the greatest lightweights to ever have lived, he won all his title matches in the lightweight divison, all but one by kayo. While Roberto Duran's original nickname was Rocky, as he began knocking out guys left, right and centre at 135, it became "Manos de Piedra" or "Hands of Stone".
There have been many great lightweights in boxing history: Joe Gans, Benny Leonard, Pernell Whitaker; and of course the legendary Hands of Stone, Roberto Duran.