Not quite the same as ECOWAS - if you scroll down the Wikipedia article to the section titled "West African Economic and Monetary Union", those are the countries that use these coins.
The West African (CFA) franc was the successor to the old French colonial currency, the French West African franc. Guinea-Bissau, the former Portuguese Guinea, also uses the CFA franc, but the former French territories Guinea and Mauretania now use their own currencies, as do Liberia and the former British colonies in the area.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis