"Hey OP, radiation safety officer here, this REALLY looks like a lead PIG used to shield a radiation source housed inside the black rod part. PIGs usually come with higher activity sources although they are occasionally with check sources. I highly recommend going down to your city’s fire department and seeing if they can scan this for you (smaller departments may not be able to do this but larger departments absolutely would have a hazmat unit that would have equipment that could) just to confirm the presence of radiation or not. If it is radioactive it might not be legal for you to own depending on the radioisotope, activity, and laws/regulations in Germany/EU."