A very nice, well struck piece.
A rarer commercially minted issue in the name of Helena.
Obverse: bust in drapery, to the right, in the rim legend:
FL HELENA AVGVSTA;
Reverse: Securitas standing left, in the rim legend:
SECVRITAS REIPVBLICE, in section ;
Bronze, diameter 19 x 20 mm, weight 3.5 g, axis 6 h.