Rare follis, R in the Roman Imperial Coinage catalogue.
Roman Imperial
Constans (337-350), Follis 340, Treweri mint
Obverse: rosette-diademed, draped and cuirassed bust right
CONSTANS P F AVG
Reverse: two soldiers standing front, heads turned inward, each holding spear and shield, one standard, M on banner between them, in exergue TRS
GLORIA EXERCITVS
Diameter 15 mm, weight 1.35 g