This is a full gold stater known as Volisios Dumnocoveros. VOL[IS]IO[S] in two lines crossed by vertical wreath of brick-like leaves facing inwards.
The other side shows a lunate horse facing left with pellet triad under open head, DVMNOC[O]VER[OS] around. This coin measures 19-21 mm and is an extremely attractive example of this type.
