Rare type of follis, R2 in the Roman Imperial Coinage catalogue.
Roman Imperial
Constantine I the Great (308-337), Follis 318, Rome mint
Obverse: laurate, draped and cuirassed bust of Constantine I right
IMP CONSTANTINVS P F AVG
Reverse: Sol standing left, chlamys across left shoulder, holding globe and raising right hand, T in wreath in left field, RP in exergue
SOLI INVICTO COMITI
Diameter 21 mm, weight 3.10 g