Iron bells are used as objects of status, tools of communication, in ceremonies an das means of payment in parts of Central Africa. They are found singly or in pairs. They have no tongues but are beaten with rubber sticks. Such iron double bells were used as currency in the late 19th century along the Ubangi River in Central Africa. Five bells would buy a pot of palm oil, for one hundred bells one would get a slave. As insignia of status and of leadership in African societies, such bells were used as early as 1000 AD, and until today.