Cuba enigmatic and little union pin with the face of Fidel Castro, 1960

This pin has the format of the pins issued by the Cuban unions, above it has the letters SRG and Havana, the central medallion has a crude portrait of Fidel Castro and below a slogan: "Unique Union", I can not give any other information, Until now, it has been impossible for me to classify, but it belongs to the time when Fidel Castro's government was fighting to impose its union leaders against the democratic syndicalist faction and that in the end it succeeded.