Very rare follis of Constantius II from the mint in Constantinople with the letter A in the left box.
There are only 7 records on Coinarchives.
Roman Empire
Constantius II (324-361), Follis 326-327, Mint of Constantinople
Obverse: bust of the emperor facing left
FL IVL CONSTANTIVS NOB C
Reverse: camp gate with two towers and an asterisk between, in the left field the letter A, CONS in exerque
PROVIDENTIAE CAESS
Weight 3.3 g