Reproduction Soviet ID container. This would have originally been made of brown or black Bakelite; ours are made from a black casting resin which picked up all the details of the original, including any small flaws. It comes with paperwork.
Many men of the Red Army threw this away believing it was bad luck, since its only purpose was for identifying your body. German soldiers frequently carried these to use as sewing needle holders since they worked much better than the paper envelopes their needles usually came in.