Very rare and original patch that was used and worn by an unknown prisoner in an unknown German concentration camp. It was removed from the striped uniform and kept as a memento by the prisoner probably. It is the Kennzeichen or identification number of the prisoner within the camp, in this case number 3920 stamped on a white patch. Patch is worn condition and has passed satisfactorily the UV test. A great piece to frame and keep as a symbol of the persecution and dehumanisation of the prisoners by Nazi Germany.