Probus, AE antoninianus, Siscia. 22 mm, 3.44 g. 

IMP CM AVR PROBVS AVG, radiate, draped and cuirassed bust right.
VIRTVS AVG, emperor standing right, holding spear and globe.
Mintmark XXI digamma (XXIS).

RIC V-2 Siscia 801; Sear 12061 var (obverse)

With permission of auctiones.ch, eAuction #42, Lot 100. Estimate: CHF 50.00