That is definitely a nice common coin. I also have one of those from the same mint as yours.

Valentinian I AE3. 364-367 AD, 2.2g, 19mm
OBV: D N VALENTINI-ANVS P F AVG, Diademed draped & cuirassed bust right.
REV: SECVRITAS REIPVBLICAE, Victory advancing left, holding wreath & palm, large variety of symbol and letter combinations in left and right fields. DSISC in ex.
REF: Cohen 37, RIC IX Siscia 7A