Constantius II, AE Follis, 327-328 AD. 

FL IVL CONSTANTIVS NOB C, laureate, draped, cuirassed bust
 left
PROVIDEN-TIAE CAESS, campgate, 2 turrets, 6 layers, star above, no doors. 

Mintmark PTRE in ex. 

RIC VII Trier 506.

With permission of Roma Numismatics, October, 2009