Watch List notes:

Constantine I (307-337). AE Follis, 324-325. Treveri mint. D/ CONSTANTINVS AVG. Laureate head right. R/ PROVIDENTIA CAESS. Camp gate with two turrets, star above; in exergue, PTR. RIC -. AE. g. 3.01 mm. 18.40 RR. Not listed in the standard references. EF.

A hybrid die pairing (a Constantine Augustus' obverse with a Constantine Caesar's reverse).