Helena. AE Follis. 327-328 AD. 

FL HELENA-AVGVSTA, diademed bust right, wearing mantle and necklace
SECVRITAS-REIPVBLICE, Securitas standing left, lowering branch with left hand, raising robe with right hand, dot STRE in ex. 

RIC VII Trier, 515, rated R4.

Contributed by Dane for Roma Numismatics, June 2009