Probus. AE Antoninianus. 281 AD. Siscia. 

IMP C PROBVS PF AVG, radiate, cuirassed bust right
SALVS AVG, Salus standing right feeding serpent in arms. 

VII in right field. 
Mintmark XXI. 

RIC V-2 Siscia 747.

With permission of Roma Numismatics, November, 2009