A nice piece. Well preserved details.
Obverse: royal bust wearing crown, armor and cloak pinned with brooch, in the rim legend:
D-G-AVGVSTVS-III-REX-POLONIARUM;
Reverse: crowned five-field escutcheon with the coats of arms of the Crown, the Grand Duchy of Lithuania and the Wettin coat of arms surmounted by the Elector's mitre, girded from below by a palm wreath, on the sides of the wreath's branches initials E.-C., between the branches the denomination mark 18., surrounded by the legend:
SAC-ROM-IMP-ARCHIM-ET ELECT-1755;