Constantius II AE18 follis of Siscia. AD 355-361.

DN CONSTAN-TIVS PF AVG, pearl diademed, draped, cuirassed bust right.
GLORIA-RO-MANORVM, Emperor, bare-headed and in military dress standing facing, head left, holding labarum and spear.

Mintmark BSIS.

RIC VIII Siscia 293/355/386 (all identical, struck at  different times).
Scarce. 

Contributed by CarpeDiem Numismatics, January, 2021