Postumus, billon antoninianus, Cologne, 1.99 g. 

IMP C POSTVMVS PF AVG, radiate, draped and cuirassed bust right.
HERCVLI MAGVSANO, Hercules standing right, right hand
on his hip, left hand on club placed on a rock.

RIC 68; Elmer 287
Very rare.
With permission of Jean Elsen & ses Fils S.A. June 2012