Constantine II AE follis, Cyzicus, AD 321-324. 20mm, 2.9 g.

DN FL CL CONSTANTINVS NOB C, laureate, draped and cuirassed bust right.
IOVI CONS-ERVATORI,Jupiter standing left, holding Victory 
and sceptre, eagle and captive at feet, X over IIMu in right
field.
Mintmark SMK Delta.

RIC VII Cyzicus 19; Sear 17126.