RARE Old Tuareg Fulani slave bracelet/Coin - bronze - Mali/Niger Africa

Manilla West African trade currency.

Manillas are (almost ring-like) bracelets, mostly in bronze or copper, very rarely of gold. They served as a kind of money or barter. They were also used as decoration in certain West African nations like Guinea Coast, Gold Coast, Calabar Kingdom, other parts of Nigeria. Manillas were also known as slave trade money. The Europeans began to use the Manillas to buy slaves for the slave trade in the Americas (as well as in England before 1807) The size and weight of a Manilla determined the exchange value.

This one looks like bronze to me but it could be brass or copper

outer diam 77mm weight 614grams

these that open almost into a weapon type way seem to be much more rare than the standard manilla bangles