Constantine I, AE follis of Siscia.

Obverse: CONSTANTINVS AVG, laureate head right.
Reverse: PROVIDENTIAE AVGG, campgate with two turrets, 
dots in top layer, star above, no doors.

Mintmark dot ASIS dot.

RIC VII Siscia 200.
With permission of Numismatik Lanz, auction 102, 2001.