Helena AE Follis AD 324-328 Cyzicus.

Obv: FL HELENA-AVGVSTA, diademed, mantled bust right,
wearing necklace.
Rev: SECVRITAS-REIPVBLICE, Securitas standing left, lowering branch and raising robe with right hand

Mintmark dot SMK Gamma dot
RIC VII Cyzicus 49, rated scarce.

Courtesy of Numismatik Lanz. Sold for 200 Euros, 2005