Silver antoninianus, 22mm, 3.28gm, issued AD 260-265. Cologne mint.
Obv: IMP C POSTVMVS PF AVG, Radiate, draped and cuirassed bust facing right.
Rev: HERC DEVSONIENSI, Hercules standing right resting on club and holding bow, lion skin over arm.
Reverse refers to the cult of Hercules at Deuso (modern Deutz), across the river from Cologne.