Chemically speaking, this molecule is "midway" concerning Sorbitan Oleate and Sorbitan Trioleate, meaning that it's also an attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the unsaturated fatty acid Oleic Acid, but in a very ratio of two:3 as a result the "Sesqui" portion within the molecule's title. If you like oil cleansers