This is a post-abdication issue for Diocletian and it is a harder to find half follis,
Diocletian, PROVIDENTIA DEORVM, Alexandria, post-abdication 93a
A.D. 308
Æ Half Follis
21mm 3.4gm
DN DIOCLETIANO FELICIS, Laureate and mantled bust r., holding olive-branch and mappa.
PROVIDENTIA DEORVM, Providentia standing r., extending hand to Quies standing l., holding branch and leaning on scepter.
In ex. ALE, in field Γ
RIC VI Alexandria 93a