Constantine I, AE follis, 21mm, 4.3g, Ticinum. 

CONSTANTINVS P F AVG, laureate draped cuirassed bust right, seen from the back. 
MARTI CON-SERVATORI, Mars standing facing, head right, in 
military dress, holding inverted spear and resting
hand on shield set on ground.
Mintmark ST.

RIC VI Ticinum 126
Contributed by David Lowe, Aug. 2014.