A nice piece.
Obverse: bust of Caesar wearing laurel wreath, armor and paludamentum, to the right, in the rim legend:
FL IVL CONSTANTIVS NOB C;
Reverse: two soldiers standing at the sides of the banner, surrounded by legend:
GLORIA EXERCITVS-; in section RwieniecGamma;
Bronze, diameter 17 x 19.5 mm, weight 1.9 g, axis 12 h.