Genuine coins usually show about ø 31 mm, 17,2 g. Silver.
Antigonus III Doson (Greek: Ἀντίγονος Γ΄ Δώσων, 263–221 BC) was king of Macedon from 229 BC to 221 BC. He was a member of the Antigonid dynasty. More on https://en.wikipedia.org/wiki/Antigonus_III_Doson