This is a Late Roman bronze coin from the era of Constantine I, dated to 300 AD. The coin is made of bronze and has been certified by H. Kogen with a Certificate of Authenticity. It is a valuable addition to any coin collection, with a historical period spanning from Roman to imperial times. The coin's fineness is unknown, but it is a rare find for collectors and enthusiasts alike. The denomination is Antoninianus, and the year is 300 AD. This coin is a piece of ancient history, perfect for anyone interested in collecting coins from this period.