Obv: Laureate head of Maxentius right with the legend IMP C MAXENTIVS P F AVG
Rev: The Dioscuri, Castor and Pollux, standing facing each other, each holding his bridled horse and resting on sceptre with the legend AETERNITAS AVG N and mint mark M OST followed by the officina mark Q in exergue
Ostia Mint (the port of Rome)
Sear 14975
Billon, 5.82 grams, 26.5 mm