Oerlikon Contraves is a Swiss anti-aircraft artillery manufacturer made famous by its Oerlikon 20 mm autocannon design of 1914, used in the First and Second World Wars, and still in use today. Copies and derivatives of these designs were used by the Germans, French, British and Japanese weapon manufacturers. Oerlikon was established in 1906 in Switzerland in the machine tool industry. In 1923 it acquired a factory in Germany. It entered the anti-aircraft defence field in 1924. In 1936 it founded a purely anti-aircraft development company called Contraves (Latin for against birds).