A nice piece.
Variety with a ring over the city shield.
Obverse: in the pearl rim the coat of arms of Elblag, in the outer rim the legend:
COIN:CIVIT:ELVI;
Reverse: in the pearl rim a shield with a crowned eagle, in the outer rim legend:
KASIMIRVS:R:POLONI;
Silver, diameter 20 mm, weight 1.33 g.