Postumus AR Antoninianus, 22.63 mm, 3.54 g. Milan. 259-268 AD. Struck by Aureolus in the name of Postumus 

IMP C POSTVMVS PF AVG, radiate, draped and cuirassed bust right.  
Rev: FIDES MILITVM, Fides standing left, holding two standards.  

RIC V-II Milan 380; cf Sear 10940 (mint). 

The bust engraving style of this coin marks it as one from the Milan mint.

With permission of Münzen & Medaillen (DE) GmbH auction 45, Lot 865, June 2017.