Constantine I, AE Follis. 328-329 AD. 

Obv: CONSTAN-TINVS AVG, Laureate head right
Rev: PROVIDEN-TIAE CAESS, campgate, 2 turrets, 7 layers, star above, no doors
Mintmark: SMKA dot

RIC VII Cyzicus 55 var (mule, with CAESS on rev.)
Second known example.

Contributed by Andreas (ABLE).

_cyzicus_RIC_VII_055_mule