Perfluoro-3,6-dioxa-4-methyl-7-octene-1-sulfonic Acid Sodium Salt
2-[1-[Difluoro[(1,2,2-trifluoroethenyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-1,1,2,2-tetrafluoroethanSulfonic Acid; 2-[1-[Difluoro[(trifluoroethenyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-1,1,2,2-tetrafluoroethanSulfonic Acid