A nice piece. Patina.
Obverse: bust of the emperor in diadem, armor and paludamentum, to the right, in the rim legend:
F L IVL CONSTANTIVS NOB C;
Reverse: Legionaries holding spears, between them banners, surrounded by legend:
GLOR-IA EXERC-ITVS, in section SMKB;
Bronze, diameter 18 x 19.5 mm, weight 3.06 g, axis 6 h.