Extracts (petroleum), heavy naphthenic distillate solvent, hydrodesulfurized; Distillate aromatic extract (treated); [A complex combination of hydrocarbons obtained from a petroleum stock by treating with hydrogen to convert organic sulfur to hydrogen sulfide which is removed. It consists predominantly of hydrocarbons having carbon numbers predominantly in the range of C15 through C50 and produces a finished oil with a viscosity of greater than 19cSt at 40 °C.]