Flan crack but very good detail.
Roman Imperial
Constantius II (324–361), Siliqua 351-355, Sirmium mint
Obverse: bust of emperor facing right
D N CONSTANTIVS P F AVG
Reverse: in the wreath VOTIS XXX MVLTIS XXXX, SIRM in exerque
Diameter 21 mm, weight 3.02 g