Constantius II. AE of Nicomedia.

DN CONSTAN-TIVS PF AVG, pearl diademed, draped, cuirassed bust right.
FEL TEMP RE-PARATIO, soldier spearing fallen horseman who is 
reaching backwards, wearing Phrygian helmet, no beard.
F in left field.
Mintmark SMN epsilon.

RIC VIII Nicomedia 65 var (officina and horseman type)
Rare

Note: RIC lists only one coin with F in the left field,
with a clutching horseman and mintmark SMNB.
The owner of the coin and I had some discussion about
the fieldmark, and it does not appear to be a Gamma with
a bit of dirt, there is definitely a central horizontal
stroke forming the F.

Collection of Saul of romanorum.com, Feb. 2011.