CIMRM 1920-1921 - White marble relief tauroctony of Aelius Maximus. Cluj, Romania.
This relief comes from the Roman fort of Castra Potaissa, at modern Turda, in Romania. The fortress was the base for Legio V Macedonica.
Arachne database entry here. This states that the monument is currently located "Cluj, Rumänien, RO, Muzeul de Istoria Transilvaniei (Museum for Transylvanian History)", and gives somewhat different measurements. It also gives bibliography: O. Doppelfeld (ed), Römer in Rumänien, Ausstellungskatalog Köln (Köln 1969) "210 Cat. no. F 80 Pl. 54."