Constantine II as Caesar, Siscia, 3. Officina, 

CONSTANTINVS IVN NOB C, laureate bust left wearing imperial 
mantle, holding Victory on globe and mappa.
VIRTVS EXERCIT, Standard inscribed VOT X, captive
seated on each side. 
S in left field, F over "HL"-monogram 
in right field. 
Mintmark: Gamma SIS Star

Ref: RIC VII Siscia 126, rated R2.

Ebay sale 2007