WW II Prisoner Train or Concentration Camp Train?

This was found at a train hub sight in far eastern Poland, directly east of Warsaw. The train area was supposed to be a place where prisoners were transferred. Is this from a train? It has an Italian language, which translated is signal alarm. What was an Italian train over there for...I know they were Axis. Would this be from a train for war prisoners or concentration camp victims? What does the metal appear to be, brass? Thanks for any help.