Watch List notes:

THE ROMAN EMPIRE
Probus, 276 – 282

Antoninianus, Siscia 276-282, billon 3.84 g. VIRTVS P – ROBI AVG Cuirassed bust l., wearing radiate helmet and holding spear and shield decorated with horseman charging r., surrounded by soldiers with shields; to l., horse's head l. Rev. ADVENTVS PROBI AVG Emperor riding l., r. hand raised, l. holding sceptre; at foot, l., captive and, in exergue, XXIT. C 56 var. (horse's head missing). RIC 634.
Very rare. An interesting and unusual obverse representation, minor
smoothing on obverse, otherwise extremely fine