Article: Swaziland is a developing country with a small economy. Its GDP per capita of $9,714 means it is classified as a country with a lower-middle income. As a member of the Southern African Customs Union (SACU) and Common Market for Eastern and Southern Africa (COMESA), its main local trading partner is South Africa. Swaziland's currency, the lilangeni, is pegged to the South African rand. Swaziland's major overseas trading partners are the United States and the European Union. The majority of the country's employment is provided by its agricultural and manufacturing sectors. Swaziland is a member of the Southern African Development Community (SADC), the African Union, the Commonwealth of Nations and the United Nations.

Now answer this question: What is the SACU?
Southern African Customs Union