Constans. AE Follis. 346-348 AD. Siscia. 

FL CONSTANTIS BEA C, laureate, draped, cuirassed bust

GLOR-IA EXERC-ITVS two soldiers holding spears and 
shields with one standard between them with o on banner. 

Mintmark Delta SIS. 

RIC VII Siscia 255. Very rare (R3).

With permission of Roma Numismatics, January, 2010