This coin is in such poor condition it is barely recognizable, which is too bad, since it is a rare type with a workshop that is not in RIC.
Constantine I
A.D. 320
18x19mm 2.9gm
CONST-ANTINVS AVG; laureate helmet and cuirassed bust.
REV: Laurel wreath enclosing VOT/ XV FEL / XX RT
RIC VII Rome 219