The Tetrassarion denomination
The tetrassarion was a bronze denomination worth 4 asses - assarion in Greek.

It was commonly struck by Roman Provincial mints, and was not struck to a standard weight but rather to some local standard. It was simply a coin worth 4 of the local basic coin denomination.
Tetrassarion

(1) Faustina II 161-176 AD
Obverse: draped bust right; ΦAVCTEINA__CEBACTH
Reverse: veiled Demeter standing half left, holding torch in each hand; ΦIΛIΠΠO_Π_OΛEITΩN
Ref: Varbanov 886 (R5)