Probus (276-282) AE Antoninianus (Bronze, 3.72g, 22mm) Ticinum, 280.
Obv: IMP C PROBVS AVG, radiate and mantled bust left, holding eagle-tipped sceptre
Rev: MARTI PACIF, Mars advancing left, holding olive branch, spear, and shield; I in left field, QXXI in exergue.
Ref: RIC 508.