this is a pretty good copy, but they got VOT on the shield backwards, however PR is right.
Constantine I
Circa A.D. 318
17mm 3.6gm
IMP CONSTANT-[INVS AVG]; high-crested helmet, cuirassed, spear over right shoulder.
VICTORIAE LAETAE P P; two Victories stg., facing one another, together holding shield inscribed TOV PR on altar with cross.
In ex. STR