Ancient Roman Follis Bronze Coin
You grade-higher grade-sharp details
Constantine I The Great. Rome Mint 321 AD. 
Obverse: CONSTAN-TINVS AVG, laureate head right.
Reverse: D N CONSTANTINI MAX AVG around decorated laurel wreath enclosing VOT/XX in two lines; 
Roman Imperial: Constantine I the Great (307-337) Follis, Ticinum (RIC-140)
Obv: CONSTANTINVS AVG.
Laureate head right.
Rev: D N CONSTANTINI MAX AVG / P T .
VOT / XX within wreath.