The Central Organisation of Finnish Trade Unions, usually referred to by the acronym SAK (Finnish: Suomen Ammattiliittojen Keskusjärjestö; Swedish: Finlands Fackförbunds Centralorganisation, FFC) is the largest trade union confederation in Finland. Its member organisations have a total of more than one million members, which makes up about one fifth of the country's population. Source: Wikipedia (en)