This reproduction is from a German Communist Rotfrontkämpferbund (Red Front fighters) badge from 1929.
Badge manufactured in 3D antique copper like the original with brooch fixing. Image as a hand on a rifle, map of the world with communist star, the letters RFB and the text on the flag reads
5 REICHSTREFFEN HAMBURG PFINGSTEN 1929
which I believe was produced for an RFB conference over easter 1929 in Hamburg.
Rotfrontkämpferbund was a workers’ self-defense organization that existed in Germany from 1924 to 1933. The organization was founded by the Communist Party of Germany in response to the growing activity of fascist militarized organizations. It consisted of communists, Social Democrats, and non-party workers over the age of 23; workers between the ages of 16 and 23 belonged to the Rote Jungfront. In 1929 the two organizations had a combined membership of 215,000