This one is being sold as a reproduction, but it wont be long until it is offered again- minus the disclaimer of it being a reproduction.
Constantius II
AE Medallion
Circa A.D. 350
DN CONSTAN-TIVS PF AVG, Draped, cuirassed bust right with laurel and rosette diadem.
LARGI-TIO, Emperor diademed, in imperial mantle and chlamys enthroned facing, wearing large belt decorated with jewels, feet on a foot-stool; he holds mappa in his left hand; with his right hand he drops coins into the fold of the robe extended towards the emperor by Res Publica, turreted and bowed; to right, Roma helmeted facing, wearing tunica, head turned towards Emperor around whose shoulders she puts her right arm, in her left hand she holds a spear.
Cohen #143. RIC 290, #404. Gnecchi, Medaglioni II, 147, 10 and pl. 136, 7.