This is an interesting coin:
DECENTIUS as CAESAR (351-353)
AE1 28x25mm 6.61g copper maiorina/double maiorina(?), minted at Trier, third series, cca. 353.
DN DECENTI - VS FORT CAES; bare-headed draped cuirassed bust r.
SALVS DD NN AVG ET CAES; large Chi-Rho flanked by A and W.
TRS
RIC VIII Trier 319/326
This specimen with large 28mm dies (of a double-maiorina?) but a weight lower, specific to the single maiorina standard of the early 350s seems to be an intermediary type between RIC 319 and 326. It is very possible that this was an intended large coin on a thinner flan, hence the 28mm dies with the weight of the 24mm dies. It was probably minted in the first half of 353, before the revolt of Poemenius ruled Decentius out of Trier.
Holed and filled(?) perhaps for further circulation after the holing(?).