Maxentius, AE follis, 26mm, Ostia. 309-312 AD. 

IMP C MAXENTIVS P F AVG, laureate head right.
AETERNITAS AVG N, the Dioscuri Castor and Pollux standing
facing each other, each holding sceptre and holding a horse
by the bridle. 

Mintmark MOSTP.

RIC 35. C. 5

Contributed by Dr. Hubert Lanz, auction November 2000, 
Added July 2011.