Mains supply in Burundi: 230 V, 50 Hz, sockets of Types C and E. 230 V means no voltage converter – only the plug shape matters.
You will find identical sockets in Cameroon, Benin, Burkina Faso and the Central African Republic. Nearby but different: Malawi, Sierra Leone and Tanzania – an adapter for Burundi will not fit there. Across Africa this setup is common: 21 of 55 countries.
Protective earth
Grounded and ungrounded sockets may occur
Burundi has sockets with a protective earth (Type E) and without (Type C). A plug that fits mechanically does not guarantee earthing.