Pyrrhos, King of Epirus and Macedonia. AE17 half unit. 274-272 BC. 4.33 g. Struck in Pella. 

Macedonian shield, PYR monogram in the centre, surrounded by six double crescents with dot in each and dot between them. 
BA-SI beneath Macedonian helmet, divided by MTR monogram, all within oak-wreath.

BMC 36 (this coin).