A very nice piece of efraim.
The coin is definitely rare in this state of preservation.
Obverse: royal bust in crown, armor and cloak pinned with a brooch, in the rim the 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 coat of arms of the Wettin family surmounted by the Elector's mitre, girded from below by a palm wreath, on the sides of the wreath's branches the initials E-C, between the branches the denomination mark 18, in the rim the legend:
SAC-ROM-IMP-ARCHIM-ET-ELECT-1755-;