A nice piece with well preserved details.
Obverse: head of Augustus in laurel wreath, to the right, in the rim legend:
CONSTAN-TINVS AVG;
Reverse: camp gate of 6 rows of bricks, with open gate, in the rim legend:
PROVIDEN-TIAE AVGG; in section PTRhalf-moon;
Bronze, diameter 19 mm, weight 3.88 g, axis 12 h.