A nice piece.
Obverse: bust of Caesar wearing laurel wreath, armor and paludamentum, to the right, in the rim legend:
CONSTANTINVS IVN NOB C;
Reverse: two soldiers standing at the sides of the banner, surrounded by legend:
GLORIA EXERCITVS; in section SMNGamma;
Bronze, diameter 17 mm, weight 2.1 g, axis 6 h.