A nice example of a Cracow trojak.
Obverse: bust of the ruler in crown and armor, with a tubular orifice, to the right, in the rim the legend:
SIG-III-D G-REX-POL-M D L-;
Reverse: denomination marking -III-, below it the coats of arms of the Eagle of the Crown, the Sheaf of the Vasa dynasty and the Pose of the Grand Duchy of Lithuania, below them the date 16-21, below it the legend in three lines:
GROS-ARGE/TRIP-REGN/POLONI, below it the Saxon coat of arms;